Highly‐fuel‐efficient Automobiles via Promoted NOx Decomposition (PND)

by Electro‐Catalytic Honeycomb (ECH)

Ta-Jen Huang Professor(tjhuangchenthuedutw)

Department of Chemical EngineeringNational Tsing Hua University

Hsinchu TAIWAN1

How to achieve high fuel‐efficiency of automobiles

bull Highest possible combustion temperatureharr highest possible fuel efficiency [thermal efficiency]

rarr Complete combustion of all precursors of combustible pollutantsrarr Gasoline direct‐injection compression ignition (GDCI) engine fueled with

light gasoline (light un‐branched open‐chain hydrocarbons [cetane]) Immediate solutions Lean burn at best economy for gasoline engines

Deleting EGR (exhaust gas recirculation) of diesel engines for highly‐increased fuel efficiencyrarr Zero pollution of NOx CO HCs amp PM The remaining issue is high NOx control

bull Removal of high to low concentration NOx under oxygen‐rich conditionrarr Removing very high NOx to near‐zero amp completely oxidizing CO amp HCs

bull NOx emission control at engine cold‐startrarr No delay on NOx control

bull No consumption of reducing agent on NOx controlrarr No remain of the reducing agent eg NH3

to cause secondary pollutionAll these done via Electro‐Catalytic Honeycomb (ECH)

The real‐world applicability of PND by ECH is confirmed by experimental data shown in the following 2

How to increase the fuel efficiency of current gasoline automobiles

For gasoline cars simply change the Air Fuel Ratio from 147 (stoichiometric burn) to 162 (lean burn for Best Economy) [as shown on the right]

3

This only needs to replace the Three‐way Catalytic (TWC) converter with the ECH

How to increase the fuel efficiency of current diesel automobiles

For diesel carsdeleting EGR to highly increase the fuel efficiency and also to highly simplify the aftertreatment system(to only one ECH)

4

This only needs to replace the Diesel oxidation catalyst (DOC) converter to the ECH and

For new cars deleting all other units (including all sensors) in the aftertreatment system

For old cars simply close EGR and stop operating all other units (including all sensorsrsquo electrical heating) in the aftertreatment system

bull GDCI engine fueled with light gasoline [light un‐branched open‐chain hydrocarbons (HCs)] can have a fuel efficiency higher than current gasoline engine by 50[S Chu A Majumdar Nature 488 (2012) 294 MA Ghadikolaei Int J

Res Eng Tech 3 (2014) 335][a reduction of greenhouse gas emission by50] with zero pollution of CO amp HCs without PM

bull Light un‐branched open‐chain HCs [cetane] alkane molecules with a cetane number of 100 ‐‐ can ignite very easily under compression

bull Fuels with higher cetane number have shorter ignition delaysrarrmore complete combustionharrless HCs amp CO emissionrarrzero pollutionrarrhigher combustion temperatureharrhigher expansion powerrarrless engine knockingharrmore smooth and quiet engine 5

Gasoline direct‐injection compression ignition (GDCI)

engine for very high fuel efficiency with zero pollution

EGR is not needed via ECH-deNOx

rarrhigher NOxlarrwelcome by PND

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

How to achieve high fuel‐efficiency of automobiles

bull Highest possible combustion temperatureharr highest possible fuel efficiency [thermal efficiency]

rarr Complete combustion of all precursors of combustible pollutantsrarr Gasoline direct‐injection compression ignition (GDCI) engine fueled with

light gasoline (light un‐branched open‐chain hydrocarbons [cetane]) Immediate solutions Lean burn at best economy for gasoline engines

Deleting EGR (exhaust gas recirculation) of diesel engines for highly‐increased fuel efficiencyrarr Zero pollution of NOx CO HCs amp PM The remaining issue is high NOx control

bull Removal of high to low concentration NOx under oxygen‐rich conditionrarr Removing very high NOx to near‐zero amp completely oxidizing CO amp HCs

bull NOx emission control at engine cold‐startrarr No delay on NOx control

bull No consumption of reducing agent on NOx controlrarr No remain of the reducing agent eg NH3

to cause secondary pollutionAll these done via Electro‐Catalytic Honeycomb (ECH)

The real‐world applicability of PND by ECH is confirmed by experimental data shown in the following 2

How to increase the fuel efficiency of current gasoline automobiles

For gasoline cars simply change the Air Fuel Ratio from 147 (stoichiometric burn) to 162 (lean burn for Best Economy) [as shown on the right]

3

This only needs to replace the Three‐way Catalytic (TWC) converter with the ECH

How to increase the fuel efficiency of current diesel automobiles

For diesel carsdeleting EGR to highly increase the fuel efficiency and also to highly simplify the aftertreatment system(to only one ECH)

4

This only needs to replace the Diesel oxidation catalyst (DOC) converter to the ECH and

For new cars deleting all other units (including all sensors) in the aftertreatment system

For old cars simply close EGR and stop operating all other units (including all sensorsrsquo electrical heating) in the aftertreatment system

bull GDCI engine fueled with light gasoline [light un‐branched open‐chain hydrocarbons (HCs)] can have a fuel efficiency higher than current gasoline engine by 50[S Chu A Majumdar Nature 488 (2012) 294 MA Ghadikolaei Int J

Res Eng Tech 3 (2014) 335][a reduction of greenhouse gas emission by50] with zero pollution of CO amp HCs without PM

bull Light un‐branched open‐chain HCs [cetane] alkane molecules with a cetane number of 100 ‐‐ can ignite very easily under compression

bull Fuels with higher cetane number have shorter ignition delaysrarrmore complete combustionharrless HCs amp CO emissionrarrzero pollutionrarrhigher combustion temperatureharrhigher expansion powerrarrless engine knockingharrmore smooth and quiet engine 5

Gasoline direct‐injection compression ignition (GDCI)

engine for very high fuel efficiency with zero pollution

EGR is not needed via ECH-deNOx

rarrhigher NOxlarrwelcome by PND

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

How to increase the fuel efficiency of current gasoline automobiles

For gasoline cars simply change the Air Fuel Ratio from 147 (stoichiometric burn) to 162 (lean burn for Best Economy) [as shown on the right]

3

This only needs to replace the Three‐way Catalytic (TWC) converter with the ECH

How to increase the fuel efficiency of current diesel automobiles

For diesel carsdeleting EGR to highly increase the fuel efficiency and also to highly simplify the aftertreatment system(to only one ECH)

4

This only needs to replace the Diesel oxidation catalyst (DOC) converter to the ECH and

For new cars deleting all other units (including all sensors) in the aftertreatment system

For old cars simply close EGR and stop operating all other units (including all sensorsrsquo electrical heating) in the aftertreatment system

bull GDCI engine fueled with light gasoline [light un‐branched open‐chain hydrocarbons (HCs)] can have a fuel efficiency higher than current gasoline engine by 50[S Chu A Majumdar Nature 488 (2012) 294 MA Ghadikolaei Int J

Res Eng Tech 3 (2014) 335][a reduction of greenhouse gas emission by50] with zero pollution of CO amp HCs without PM

bull Light un‐branched open‐chain HCs [cetane] alkane molecules with a cetane number of 100 ‐‐ can ignite very easily under compression

bull Fuels with higher cetane number have shorter ignition delaysrarrmore complete combustionharrless HCs amp CO emissionrarrzero pollutionrarrhigher combustion temperatureharrhigher expansion powerrarrless engine knockingharrmore smooth and quiet engine 5

Gasoline direct‐injection compression ignition (GDCI)

engine for very high fuel efficiency with zero pollution

EGR is not needed via ECH-deNOx

rarrhigher NOxlarrwelcome by PND

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

How to increase the fuel efficiency of current diesel automobiles

For diesel carsdeleting EGR to highly increase the fuel efficiency and also to highly simplify the aftertreatment system(to only one ECH)

4

This only needs to replace the Diesel oxidation catalyst (DOC) converter to the ECH and

For new cars deleting all other units (including all sensors) in the aftertreatment system

For old cars simply close EGR and stop operating all other units (including all sensorsrsquo electrical heating) in the aftertreatment system

bull GDCI engine fueled with light gasoline [light un‐branched open‐chain hydrocarbons (HCs)] can have a fuel efficiency higher than current gasoline engine by 50[S Chu A Majumdar Nature 488 (2012) 294 MA Ghadikolaei Int J

Res Eng Tech 3 (2014) 335][a reduction of greenhouse gas emission by50] with zero pollution of CO amp HCs without PM

bull Light un‐branched open‐chain HCs [cetane] alkane molecules with a cetane number of 100 ‐‐ can ignite very easily under compression

bull Fuels with higher cetane number have shorter ignition delaysrarrmore complete combustionharrless HCs amp CO emissionrarrzero pollutionrarrhigher combustion temperatureharrhigher expansion powerrarrless engine knockingharrmore smooth and quiet engine 5

Gasoline direct‐injection compression ignition (GDCI)

engine for very high fuel efficiency with zero pollution

EGR is not needed via ECH-deNOx

rarrhigher NOxlarrwelcome by PND

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

bull GDCI engine fueled with light gasoline [light un‐branched open‐chain hydrocarbons (HCs)] can have a fuel efficiency higher than current gasoline engine by 50[S Chu A Majumdar Nature 488 (2012) 294 MA Ghadikolaei Int J

Res Eng Tech 3 (2014) 335][a reduction of greenhouse gas emission by50] with zero pollution of CO amp HCs without PM

bull Light un‐branched open‐chain HCs [cetane] alkane molecules with a cetane number of 100 ‐‐ can ignite very easily under compression

bull Fuels with higher cetane number have shorter ignition delaysrarrmore complete combustionharrless HCs amp CO emissionrarrzero pollutionrarrhigher combustion temperatureharrhigher expansion powerrarrless engine knockingharrmore smooth and quiet engine 5

Gasoline direct‐injection compression ignition (GDCI)

engine for very high fuel efficiency with zero pollution

EGR is not needed via ECH-deNOx

rarrhigher NOxlarrwelcome by PND

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Electro‐Catalytic Honeycomb (ECH)‐deNOx mdasha real‐world device for Promoted NOx Decomposition (PND)bull Lower emission of greenhouse gases (GHG) needs higher fuel efficiency ie lower fuel (energy) consumption rarr cost down via PND

bull Currently fuel efficiency is inhibited by difficulty in deNOx technologies (SCR reductant supply NSR storage capacity limithellip) to treat an exhaust with high NOx concentration

bull TWC can not treat lean‐burn exhaust

bull Higher combustion temperature leads to higher fuel efficiency but also higher NOx concentration in the exhaust This is inevitable since the following reactions occur during combustion using air (N2 + O2 )

Initiation O2 rarr 2O (thermal cracking mdash providing O for combustion)Chain reaction O + N2 rarr NO + N N + O2 rarr NO + OTermination NO + O rarr NO2

bull This deNOx difficulty has been resolved by PND with ECH NOx decomposition for automotive emission control 6

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

NOX‐soot trade‐offduring EGR ofdiesel engine

[A Maiboom et al Energy 33 (2008) 22]

7

Old tech

New tech (PND)

Current diesel engines have sacrificed the fuel efficiency to

lower NOx concentration by exhaust gas recirculation

(EGR)

Diesel exhaust causes cancer (WHO 2012612)-- Diesel engine exhaust fumes are a definite cause of lung cancer

soot NOx outdoor air pollution (WHO 20131017)rarr What should we do Not driving diesel automobiles rarr Deleting EGR

needing diesel particulate filter larr

soot particulate matter (PM)

However those very small particulates which can go through the filter can penetrate deep into the lung [American Lung AssociationCalif]

rarr Increasing fuel efficiency at least by

burning more sootprecursor in the enginerarr reduce soot emission

rarr Deleting EGR saving both health amp fuel

World Health Organization

eg SCR(SelectiveCatalyticReduction)

Deleting EGR

Deleting EGRdarr

rarrIncrease combustion temperature in enginerarr Increased NOx ()

preferred

Electro-catalytic honeycomb (ECH) enables saving health amp fuel

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

8

The most important lean‐burn combustion processes are that of gasoline engine beingconverted from stoichiometric-burn to lean-burn amp that of diesel engine deleting EGR 30 autorsquos fuel savinglarr deNOx by Electro-Catalytic Honeycomb (ECH)

ECH looked the same as TWC(Three‐way Catalytic) converter

-- for stoichiometric-burn engine

ECH-deNOx reactor for lean-burn engine

This presentation

ECH-deNOx is simpler than TWC (stoichiometric operation)since ECH-deNOx(best for CI engine)does not need control system for engine operation[CI compression ignition]

Engine exhaust pipe

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

The ECH works on Promoted NOx Decomposition (PND) ie emf-promoted direct NOx decomposition

NOx (NO+NO2) rarr N2+O2

Electro-Catalytic Honeycomb (ECH) for lean NOx emission control

Typical deNOx characteristics of PND arebull No consumption of reducing agent or else

[purely decomposition] Care freebull Higher O2 concentration results in higher

deNOx rate [due to increased promotion with emf] Simultaneous oxidation of hydrocarbons

CO amp Particulate Matter (PM) feasiblebull Higher NOx concentration can result in higher

deNOx rate [obeying reaction kinetics] Highly fuel‐efficient engines

bull Relatively constant deNOx rate at very low NOx concentration [due to a specific reaction mechanism] near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOxfrom ambient temperature no treatment delay amp deNOx at cold weather

bull Presence of H2O amp CO2 beneficial amp SO2 OK no N2O formation

bull No use of precious metal EconomicalThese characteristics are all based on the inventorrsquos published results

ECH [EU patent granted ampother patent applications filed]

10 Electro-catalytic honeycomb (ECH)11 Anode forming ECH structure111 amp 112 outer amp inner surface

of the anode structure12 Exhaust flow channel13 Shell covering the outer surface

of the anode structure20 Electrolyte layer coated on the inner

surface of the anode structure30 Cathode layer facing the exhaust flow

channel for exhaust treatment

[as automotive catalytic converter]

promoted NOxdecomposition

electrochemical cell (generating emf)

electrochemical cell (generating emf)

promoted NOxdecomposition

Electromotive force (emf) is generated when there is a

difference in oxidationreductionpotentials of CathodeAnode and increases with potential difference

[electrochemical double-cell]The EDC consists of two electrochemical cells

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

10

These are typical characteristic curves forpromoted NOx Decomposition

for lean deNOx of combustion processes

Secondary air is beneficial

The ECH works on promoted NOx decomposition (PND)

no treatment delay amp no temperature window

Very high NOx concentration preferred

diesel exhaust diesel exhaust diesel exhaust

[TJ Huang et al Chem Eng J 203 (2012) 193]

[TJ Huang et al Appl Catal B 110 (2011) 164][TJ Huang et al Appl Catal A 445ndash446 (2012) 153]

Temperature (C)

100 150 200

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

4

5

6

7

deN

Ox

rate

( m

ole

NO

xm

in

-1cm

-2

)

01

02

031800 ppm NOx360 ppm NOx

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

deNOx characteristics of emf‐promoted decomposition of NOx

bull Very high NOx concentration preferred Highly fuel‐efficient enginesamp ECH‐deNOx does not need any control on engine operation no control system is needed

bull No consumption of reductant or anything else Care freebull Effective at high O2 concentration the higher the better

Simultaneous oxidation of hydrocarbons CO amp PM feasible

bull No temperature window amp effective deNOx from ambient temp no treatment delay amp deNOx at cold weather

bull ECH similar size to SCR converter (shown next) Very compact size for automobiles

bull No use of precious metal Economicalbull H2O amp CO2 beneficial amp SO2 OK no N2O formationbull Zero pollution (near-zero NOx emission) 11

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

For SCR‐deNOx onboard of heavy‐duty Diesel vehicles with commercial V2O5WO3ndashTiO2 catalyst on standard metal substrates with a cell density (~honeycomb)

of 400 cpsi the highest activity for 1000 ppm NO at 52000 hminus1 amp 400 degC is124 μmole NO∙min‐1∙cm‐2[O Krocher M Elsener Appl Catal B Environ 75 (2008) 215]

Note SCR‐deNOx activity of0024 μmole NO∙min‐1∙cm‐2 was reported for treating 250 ppm NO with catalyst plate[X Fan et al Catal Commun 12 (2011) 1298]

12

Real‐world automotive applications

The ECH-deNOx activityis comparable to the

real-world automotiveSCR-deNOx activity

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Shortages in currentautomotive deNOx technologies

bull Three‐way catalytic (TWC) converter (honeycomb)Engine operation must be adjusted to accommodate the exhaust treatment The usage of precious metals Stoichiometric burn mdash low fuel efficiencyTreatment delay ‐‐ the catalyst is not effective at ambient temperature and thus a heating period is required [for all current deNOx via reduction or storage]

bull Exhaust Gas Recirculation (EGR)To result in low NOx concentration in exhaust at the expense of fuel efficiency

bull Selective Catalytic Reduction (SCR)The consumption of reducing agents eg ammonia in urea‐based SCR (costly amp inconvenient refilling) The formation of N2O a strong greenhouse gas

bull NOx Storage and Reduction (NSR) mdash lean‐NOx trapThe consumption of fuel for NOx treatment Limited storage capacity

bull Electrochemical NOx Reduction with applied voltage (electrical current)

The consumption of electricity with low current efficiency 13

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

NOx NO amp NO2NO N + O (previously needing removal by reductant NH3COHCs)

darr darr SCRuarrTWCuarr

N2 O2 (continuously promoted oxygen desorption‐‐PND)uarr

NO2 NO + OO2 2O

SOx SO2 amp SO3SO2 rarr 18S8 + 2Orarr O2 (promoted oxygen desorption)SO3 SO2 + O

14

promoted NOx decomposition--PND vs LNTNSR amp SCRpromoted SOx decomposition--PSD

continuously promoted oxygen desorption by the presence of a voltage(an electromotive force emf)

Principle for emf-promoted decomposition

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Publications supportinglean deNOx by promoted NOx decomposition (PND)underlined is the inventor of the ECHbull Ta‐Jen Huang CL Chou Electrochem Comm 11 (2009) 477ndash480bull Ta‐Jen Huang CL Chou J Power Sources 193 (2009) 580ndash584bull Ta‐Jen Huang CL Chou J Electrochemical Society 157 (2010) P28ndashP34bull Ta‐Jen Huang CL Chou Chem Eng J 160 (2010) 79ndash84bull Ta‐Jen Huang CL Chou Chem Eng J 162 (2010) 515ndash520bull Ta‐Jen Huang IC Hsiao Chem Eng J 165 (2010) 234ndash239bull Ta‐Jen Huang CY Wu YH Lin Environmental Science Technology 45 (2011) 5683ndash5688bull Ta‐Jen Huang CY Wu and CC Wu Chem Eng J 168 (2011) 672ndash677bull Ta‐Jen Huang CY Wu CC Wu Electrochem Comm 13 (2011) 755ndash758bull Ta‐Jen Huang CY Wu CC Wu Chem Eng J 172 (2011) 665ndash670bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Energy Environmental Science 4 (2011) 4061ndash4067bull Ta‐Jen Huang CH Wang Chem Eng J 173 (2011) 530ndash535bull Ta‐Jen Huang CY Wu SH Hsu CC Wu Appl Catal B Environmental 110 (2011) 164ndash170bull Ta‐Jen Huang CY Wu Chem Eng J 178 (2011) 225ndash231bull Ta‐Jen Huang CH Wang J Electrochemical Society 158 (2011) B1515ndashB1522bull Ta‐Jen Huang SH Hsu CY Wu Environmental Science Technology 46 (2012) 2324ndash2329bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Chem Eng J 203 (2012) 193ndash200bull Ta‐Jen Huang CY Wu DY Chiang CC Yu Appl Catal A Gen 445ndash446 (2012) 153ndash158bull Ta‐Jen Huang CY Wu DY Chiang J Ind Eng Chem 19 (2013) 1024ndash1030 15

Power generation with NOxsubstituting O2

-- NOx decomposition in rich oxygen

-- promoted by both voltageamp oxygen-ion migration

NOx decompositionat (promoted by)open-circuit voltage(electromotive force emf)

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

with applied voltagemdash oxygen pumping

16

with power generationmdash solid oxide fuel cell (SOFC)‐‐ continuous presence of an OCV

for power generation

emfharropen‐circuit voltage (OCV) of fuel cell

Anode fuel HCs etcno anode fuel needed

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Schematic description of bi‐pathway dominated oxygen reduction on SOFC cathode

[M Gong RS Gemmen X Liu J Power Sources 201 (2012) 204] 17

O2 + 2eminus 2Ominus

Oxygen can be simply desorbed2Ominus rarr O2

Without discriminating the source of O NOxO

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Lean deNOx byemf-promoted decomposition of NOx

18

2NO + [ ][ ] rarr N－[O][O]－N 2nd orderN－[O][O]－N rarr N2 + [O][O]

[O][O] rarr O2 + [ ][ ]

NO rarr N + O ∆H298 = -216 Kcalmole (exothermic)NO2 rarr N + O2 ∆H298 = -8 Kcalmole

The presence of a voltage weakens the chemisorptive bond strength of the O species[CG Vayenas S Bebelis Catal Today 51 (1999) 581] facile desorption of oxygen

for emf-promoted decomposition of NOx

at high enough NO concentration

2NO rarr N2 + O2

rN2 = k [NO]2Higher NO concentration is highly preferred(according to kinetic law)

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Electrochemical cellLSC ndashGDC cathodeCatalystLSC ndashGDC(La06Sr04CoO3 ndashCe09Gd01O195)14 O2 10 H2O 10 CO2 600oC 19

Principle and proof foremf-promoted decomposition of NO rarr N2 + O2

1000 2000 3000 4000 5000 600005

10152025

3000

3500

4000

4500

5000

cell at OCVcatalyst

N2 f

orm

atio

n ra

te ( m

ol m

in-1

g-1 )

Inlet NO concentration ( ppm )

OCV open-circuit voltage(solid oxide fuel cell operationwithout consuming anode fuel

ie reductant)~ electromotive force (emf )

Over the catalyst in a conventional reactor the formed N species from direct NO decomposition can be easily associated to form N2 however the formed O species is strongly adsorbed and facile desorption of the Ospecies as O2 into the gas phase is very important[Y Teraoka et al J Chem Soc Faraday Trans 94 (1998) 1887]

Electrochemical cell can be solid oxide fuel cell(SOFC) --1st stage of this tech electrochemical-catalytic cell (ECC) electro-catalytic tube (ECT)and EDC in electro-catalytic honeycomb (ECH)

The deNOx rate via emf-promoted decomposition is two orders higher than that over conventional catalyst via direct decomposition

Inlet NOx concentration (ppm)0 500 1000 1500 2000 2500

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

500

1000

1500

2000

deN

Ox

rate

( m

ole

NO

xm

in

-1g

-1

)

0

4

8

12

16ECHCatalyst

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

The application fields of ECH Schematics of ECHLight‐Duty Vehicles and Trucks Gasoline passenger cars amp Motorcycles Diesel passenger cars (ECH‐deNOx) Pickup trucks

10 ECH 11 anode forming the structure of the ECH 111 and 112 outer and inner surface of the anode structure respectively 12 exhaust flow channel 13 shell covering the outer surface 111 20 electrolyte layer coated on the inner surface 112 30 cathode layer facing the exhaust

flow channel for exhaust treatment (EU patent)

Heavy‐Duty Highway Engines and Vehicles Compression‐ignition (CI) engines [GDCI] Urban buses Trucks (ECH‐deNOx) Long distance buses Recreational vehicles Long haul trucks Spark-ignition (SI) engines rarr Lean burnNonroad Engines and Vehicles Aircraft CI engines (underground mining sea oil platformhellip) Locomotives (ECH‐deSOx amp deNOx) Marine CI engines Recreational engines and vehiclesStationary sources Power plant boilers (burner) Gas turbines Fertilizer plants Cement plants Large boilers (ECH‐deSOx amp deNOx) Medium boilers (in Hospitals Care centershellip) Small boilers (Household boilers)

Other Combustion exhausts (ECH‐deSOx amp deNOx)

The fields for applications of ECH

EDC

Electrochemical double‐cell (EDC)

Electro‐catalytic honeycomb (ECH)

EDC platefor PND testingwith or without metal plate

The anode side should be enclosed completely by dense layer (seal)

Metal plate

SO2rarr 18S8+O2

seal

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities

Concluding Remarks

21

bull Lean deNOx by promoted NOx decomposition (PND) no consumption of reductant (no NH3 slip) or other resource

bull Higher O2 concentration preferred for deNOx simultaneous oxidation of hydrocarbons (HCs) CO amp

Particulate Matter (PM) feasiblebull Very high NOx concentration preferred for deNOx very high temperature in engine allow deleting EGR

minimize HCs CO amp PM formation in enginebull Relatively constant deNOx rate at very low NOx concentration near‐zero NOx emission can be achieved

bull No temperature window amp effective deNOx from ambienttemperature no treatment delay

Thus especially with GDCI (light Gasoline Direct‐injection Compression Ignition) ECH‐deNOx can result in

zero pollution of automobilesto help Creating Healthy Livable Cities