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| 2003 ,Vol.12 ,No.2,123-119 |
ISSN 1003-9953
CN 21-1484/O4 |
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| Characterization and Activity of Cr, Cu and Ga Modified ZSM-5 for Direct Conversion of Methane to Liquid Hydrocarbons |
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| Abstract Direct conversion of methane using a metal-loaded ZSM-5 zeolite prepared via acidic ion
exchange was investigated to elucidate the roles of metal and acidity in the formation of liquid hydrocarbons.
ZSM-5 (SiO2/Al2O3=30) was loaded with di erent metals (Cr, Cu and Ga) according to the
acidic ion-exchange method to produce metal-loaded ZSM-5 zeolite catalysts. XRD, NMR, FT-IR and
N2 adsorption analyses indicated that Cr and Ga species managed to occupy the aluminum positions in
the ZSM-5 framework. In addition, Cr species were deposited in the pores of the structure. However, Cu
oxides were deposited on the surface and in the mesopores of the ZSM-5 zeolite. An acidity study using
TPD-NH3, FT-IR, and IR-pyridine analyses revealed that the total number of acid sites and the strengths
of the Bronsted and Lewis acid sites were signi cantly di erent after the acidic ion exchange treatment.
Cu loaded HZSM-5 is a potential catalyst for direct conversion of methane to liquid hydrocarbons. The
successful production of gasoline via the direct conversion of methane depends on the amount of aluminum
in the zeolite framework and the strength of the Bronsted acid sites. |
KEYWORS:
characterization
activity
modified ZSM-5
methane
direct conversion
liquid hydrocarbons
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