Activity of carbided molybdena-alumina for CO2 hydrogenation

The relationship between the catalytic activity of carbided molybdena-alumina and the methane desorption from carbidic carbon through temperature-programmed surface reaction (TPSR) were studied. The effects of passivation and hydrogen treatment on the catalytic activities of molybdenum carbides for CO2 hydrogenation were determined. When the 973 K-carbided catalyst was reduced at 773 K with hydrogen, the catalyst exhibited the highest activity for the reaction, the activity decreasing with increasing H-2 pretreatment temperature. Passivation of this catalyst decreased the reaction rate by 20%. TPSR results were correlated with the activity to reveal that molybdenum carbide with slightly deficient carbidic carbon (Mo2C0.96<Mo2C1.0) serves as an active site for CO2 hydrogenation. (C) 1998 Elsevier Science B.V. All rights reserved.