The activity of several molybdenum compounds for the methanation of CO2

Several molybdenum compounds-oxides, sulfide, metal, carbide, and nitride—were prepared, and their catalytic properties in the hydrogenation of CO2 at 350 °C were investigated and compared with those of nickel and iron. The initial specific activities, rates per unit surface area of catalyst, decreased in the sequence Ni > Mo carbide > Mo metal > Mo nitride > MoO2 > MoS2 > MoO3. Iron deactivated so rapidly that its initial activity could not be determined. The molybdenum compounds produced very much smaller amounts of C2 and C3 hydrocarbons in the hydrogenation of CO2 than in that of CO. Iron produced the largest amount of higher hydrocarbons from CO2, and Ni only CH4. The molybdenum compounds, except MoS2 and MoO3, had high activities for watergas-shift reaction.