Acidity and catalytic properties for methane conversion of Mo/HZSM-5 catalyst modified by reacting with organometallic complex

The selective modification of the external surface of HZSM-5 by large organometallic complexes was used to reduce the densities of external acid sites and MoOx species retained at external surfaces during the exchange process. The amounts of acid sites and the catalytic properties for non-oxidative aromatization of methane over modified and unmodified samples were studied by NH3-TPD, FT-IR of d3-acetonitrile adsorption, and TGA measurements. It was found that acid sites and active MoOx species mainly located within the channels of the modified zeolites, and these modified Mo/HZSM-5 catalysts showed higher shape-selectivity to major product benzene and lower formation rates and selectivities for large hydrocarbons that normally cause the deactivation of catalysts.