In situ GaK edge XANES study of the activation of Ga/ZSM-5 prepared by chemical vapor deposition of trimethylgallium
Hensen, EJM × Garcia-Sanchez, M Rane, N Magusin, Pieter Liu, PH Chao, KJ van Santen, RA #
Catalysis Letters vol:101 issue:1-2 pages:79-85
The activation of a dimethylgallium/ZSM-5 precursor to well-defined reduced and oxidized species is studied by in situ Ga K edge XANES. The precursor is prepared by chemical implanting of trimethylgallium on acidic HZSM-5. Subsequent reduction leads to charge-compensating Ga+ species. Direct oxidation of the trimethylgallium precursor leads to various forms of gallium oxide and regeneration of Brønsted acid protons. Oxidation of the reduced Ga+ species yields predominantly to GaO+ species. The GaO+ species exhibit a much higher H2/D2 exchange activity than reduced Ga+ species.