Journal of Catalysis, Vol.190, No.2, 276-283, 2000
Selective dehydroaromatization of methane toward benzene on Re/HZSM-5 catalysts and effects of CO/CO2 addition
The novel rhenium catalyst Re/HZSM-5 was studied for the catalytic performance of methane dehydrocondensation at 3 atm and 873-1023 K. It was found that C-2 hydrocarbons and aromatic compounds such as benzene and naphthalene were catalytically obtained with a considerable evolution of hydrogen. High methane conversion (8-12%) and rates of benzene formation obtained on the Re/HZSM-5 catalyst were similar, under the experimental conditions used, to that on Mo/HZSM-5, which has been thought to be a unique catalyst for the reaction. In contrast to the molybdenum carbide (Mo2C) as the active phase for the reaction on Mo/HZSM-5, EXAFS and TG/DTA/mass studies suggest that the metallic Re on HZSM-5 is responsible for the catalytic dehydrocondensation of methane toward C2 hydrocarbons, benzene, and naphthalene. High and stable conversion of methane and high selectivities (70-87% based on carbon) of C-2 hydrocarbons and benzene have been attained in the catalytic dehydrocondensation of methane on Re/HZSM-5 with CO/CO2 added in methane feed. (C) 2000 Academic Press.
Keywords:ION ZSM-5 ZEOLITES;MO/HZSM-5 CATALYSTS;CONVERSION;DEHYDROGENATION;AROMATIZATION;OXYGEN;NAPHTHALENE;ABSENCE;ACTIVATION;MO/ZSM-5