Nanotechnology In CatalysisA Decade of Progress and Into the Future

S. Mark Davisat NSF Grantees Conference

on NSE, Dec. 6-8, 2010

Nanotechnology In Catalysis

NSF Workshop 2003—M.E. Davis, T.D. Tilley, et.al.WTEC Follow-On Study 2007—R.J. Davis et.al.

• Grand Challenge: Control composition and structure over length scales from 1 nanometer to 1 micron to provide catalytic materials that accurately and efficiently control reaction pathways

– Catalysts are engines that power the world at the nanometer scale– Catalysts are the most successful application of nanotechnology– Technologies contribute to ~ 1 T$ revenue in US and ~30% of GDP

Nanocatalysis Is The “Science Of Synthesis And In-situ Characterization OfSupramolecular Materials….It Differs From Traditional Catalysis Since The Materials Are Explicitly Designed Over Length Scales Larger Than Single

Active Sites”...... R. Schlogl, S. Hamid; Angew. Chem. Int. (2004)

~ 880 Million

Gallons Per Day (World Wide)

3.2 Billion 1.9 Billion

Crude Production

Refining & Chemicals Fuel

Gasoline

Diesel/Gasoil

~ 980 MillionToday’s Infrastructure• Massive• Global• Highly Efficient• 100 Years in Making

Large and Complex Industry

~ 300-400 MillionChemicals

• Energy Efficiency • New Economies on the Rise• Integration of Energy Networks• Environmental Regulations

• Crude Quality• Sources

Production

• CO2 Mgmt.• Reduced Emissions

Refining& Chemicals

• Reduced Emissions

• Adv. ICEs

Vehicles

• Molecularly Tailored Fuels

Fuels

Agents of Change

Catalytic Material Challenges

HA

C9

C6

+ H++

.

+

+

H+ +

H+ +

H+ + A-

.

• Mesoporous and multifunction materials • Poison resistant metals and metal compound catalysts• Shape selective catalysts for fuels and chemicals• Pore system design to optimize mass transport vs kinetics

Tailored Structure and Structure/Property Control at Nanoscale Critical for Next Generation Catalysts

High Throughput R&D Improving Technology Delivery

REFINING

SCANFiningTM

ULS Diesel

NebulaTM

MSDWTM

MAXSATTM

EMOGASTM

CHEMICALS

XyMaxSM

PxMaxSM

TransPlusSM

EBMaxSM

Cumene

OLGONESM

Advanced Catalyst Technology

Kinetics & Models

AdvancedCharacterization

Catalyst / Process Scale-up

HTE Synthesis & Testing

60Å

100Å

20Å

40Å

Zeolite YZSM-5

Pore Size A

406080100

5

10

20

MCM-41

Gasoil ResidsGasolineChemicals

°

Shape Selective Catalysis Key to Managing Molecular Size & Shape

• MCM-41 Recent Commercial Nanotechnology Example

Aromatics

FCC

Surfactant Micelle

Micelle RodHexagonal Array

Calcination

MCM-41

Silicate

MCM-41: Early Example of Self Assembly

Clad the Surface

Vary Chemical

Composition

Vary Pore Size1.5nm to >10nm

Anchor Metalsand Catalysts

Many Options for Tailoring Microstructure

and Reactivity

Lube Dewaxing: Shape-Selectivity in Action

• EM Hydroisomerization Technology Is Industry’s Most Selective, Highest Yield Lubricant Dewaxing Technology

Wax Molecule

Bulky LubricantMolecule

Large Molecule Cannot Enter Zeolite Pore

Unchanged Bulky Lubricant Molecule

Lubricant Molecule

Tailored 1-d Zeolite Catalyst

Go

• New Form Of Shape Selectivity• EB Production Using MCM-22

– Structural Features» 12-R cavities (A) via

10-ring windows (B)» 12-R surface pockets (D)

• Alkylation Occurs In Surface Pockets• Multiple Alkylation In Cages Avoided

“ Surface Pocket Catalysis”

D

D+

Recent Commercial Applications

Topsoe BRIMTM Diesel HDS Catalysts• R&D enhanced by fundamentals understanding • Promoted MoS2 crystallites have 1-D metallic

“brim” states that contribute to activity

STM image3 nm MoS2

Univ. Aarhus

Topsoe FENCETM Catalysts forMethanol Synthesis

• Higher activity and longer lifetime• Cu-sintering inhibited by “picket fence” • Cu/ZnO interaction stabilizes copper • ZnO separation by Al203 provides barrier

Images Reproduced with Permission of Haldor Topsoe Inc.

Recent Commercial Applications

NxCatTM System for Naphtha Reforming• Hexagonal Pt(111) favors

aromatics—Davis, Somorjai • High area catalyst developed/demonstrated

2008—Zhou et.al., Headwaters

NxCatTM for Direct HydrogenPeroxide Synthesis

• Uniform 4 nm PtPd particles• (110) structure gives selectivity• Commercial demonstration by

Headwaters/Evonik • 2007 EPA Green Chemistry Award

Images Reproduced with Permission of Headwaters Inc.

National Lab Activities

Raft Structures on Alumina • Peden, et.al. (PNNL/ORNL); Science (2009)• High field NMR and STEM enables unique

probing of metal support interaction• PtO rafts anchor to “penta-coordinate”

aluminum sites

New Synthesis Methods for Nano-particles• Nenoff et.al. (SNL); J.Phys Chem. C (2009)• Photo-reduction produces homogeneous alloy

nano-particles in normally immiscible systems• Complements “core-shell” systems

HRTEM--AgNi 50/50

Images Reproduced with Permission of Authors.

New Science—Future Platforms??

Tailored Emulsions for PhaseTransfer Catalysis

• D. Resasco et.al.; Science (2010)• Pd/CNT/oxide nanoparticles stabilize

emulsions, do catalysis at interface• Simplified biofuels processing

Energy Conversion Based on Catalysis• Hot electrons generated in catalyzed

reactions can be converted to currentin nano-diode structures

• Somorjai, et.al.; JACS (2005)

Images Reproduced with Permission of Authors.

New Science—Future Platforms??

Selective Syngas Conversion to Ethanol• X. Bao et.al.(DICP); Nature Materials (2007)• RhMn particles inside nanotubes 10x more

active than particles outside • Host-guest electronic interaction??

Highly Selective Epoxidation• Tilley, Ruddy; JACS (2008)• Single site tantalum alkoxide

species in mesoporous silicagive 99% epoxide selectivity

• Ta(η2-O2) intermediate

MesoporousSBA15 Silica

Images Reproduced with Permission of Authors.

Structure Control in Powders and Pellets

Non Classical Synthesis and New Fabrication Methods: New precursors, metastable structures, structure directing methods Control particle size, shape, and surface structure

Morphology and Distribution: Placement of active species, promoters in specific environments Pore system design

Modifying Site Functionality: Acid site strength and density, promoters, multifunction systems

Advanced Characterization and Chemistry Fundamentals:

....

....

Lessons Learned

• Breakthrough Discovery Isn’t Easy

• Cost Effective Development andCommercialization Is Harder

• Partnerships, High Throughput Methods, and Modeling Are Decreasing CycleTimes to Commercialization

• Coupling Nanotechnology Developers withApplications Developers is Essential- Universities and National Laboratories- Spin-off companies- Established technology suppliers

Significant Recent Progress—Promising Future Potential