alkaline treatment on commercially available aluminum rich mordenite
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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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