alkaline treatment on commercially available aluminum rich mordenite

Alkaline treatment on commercially available aluminum rich mordenite

—read the literature with a critical view

报告人：张丽康导 师：刘国柱

A.N.C. van laak et al. / Applied Catalysis A: General 382 (2010) 65–72

2012/12/01

Whatever the stand of the literature, we can still learn something…

Results

1) H-MOR-1M-15min: Inter-crystalline porosity and mesoporous volume: 0.01 0.21 cm3 · g−1 External surface area: 36 85 m2 · g−1 Microvolume and crystallinity were preserved2) Na-MOR requires longer contact time to obtain similar porosity3) Changing the contact time and alkaline concentration,

intracrystalline mesoporosity can be obtained for mordenite with Si/Al ratio as low as 10

4) The increase in activity is soly related to the shorter diffusion pathlength, but not the increase in acid site density

three agglomerated small mordenite crystallites

Experiments

Na-LZM-5(Si/Al Ratio-5.7)

• H-MOR-at-0.2M-30min• H-MOR-at-0.5M-30min• H-MOR-at-1.0M-30min• H-MOR-at-1.0M-15min• Na-MOR-at-1.0M-5,10,15,23,30,45,60,90,120min

Na-BASF(Si/Al Ratio-8.5)

• Na-BASF-at-1.0M-15min

NH4-CBV 21A(Si/Al Ratio-10)

• NH4-CBV 21A-at-1.0M-10min• NH4-CBV 21A-at-0.5M-20min

J.C. Groen, T. Sano, J.A. Moulijn, J. Pérez-Ramírez, J. Catal. 251 (2007) 21–27

Materials

ExperimentsCharacterization

XRD-crystallinity

N2 ad/desorption

SEM ＆ TEM

27Al MAS NMR

NH3-TPD

TEOM-cumene uptake

t-plot method: Vmeso； Vmicro； SextBJH-method: pore size distribution

ExperimentsCatalytic

measurementsbenzene

propene

cumene

activity

selectivity

discussion

J.C. Groen, T. Sano, J.A. Moulijn, J. Pérez-Ramírez, J. Catal. 251 (2007) 21–27

35nmInter-

crystalline

H-LZM-5(Si/Al Ratio-5.7)

discussion

L.I. Meza, M.W. Anderson, J.R. Agger, C.S. Cundy, Z.G.J.C.a.W.Y. Ruren Xu, Stud.Surf. Sci. Catal., Elsevier (2007) 177–184.

discussion

Na-LZM-5(Si/Al Ratio-5.5)

Similar pore size distribution with longer contact time was obtained for Na-LZM-5comparing with H-LZM-5.

Reason 1: larger cations protection in Na-LZM-5

Reason 2: structural defects formed by extra-framework aluminum after

calcination

discussionBASF (8.5)and CBV 21A (10)

3-8nm

Pore size distribution

is more diverse

Average pore size is 100nm

discussionbenzene alkylation with propylene H-LZM-5-parent VS H-LZM-5-at-1.0M-15min

M.S. Holm, S. Svelle, F. Joensen, P. Beato, C.H. Christensen, S. Bordiga, M. Bjørgen, Appl. Catal., A 356 (2009) 23–30.

No strong Lewis acid sites formed; acid site density increased slightly

Increasing activity is not related to acid density and strength

Decrease in diffusion distance because of intra- and inter-crystalline mesopores

Thanks for attention!

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