SELECTIVE HYDROGENATION OF CO2 TO CO IN THE PRESENCE OF EXCESS CO ON A MOO3/ZNO CATALYST - A PRELIMINARY ATTEMPT TO YIELD AN EQUIMOLECULAR MIXTURE OF H-2 AND CO

MoO3/ZnO and NiO/ZnO were subjected to the reverse water gas shift reaction(CO2 + H-2 --> CO + H2O) at 903 K with excess CO. Carbon deposition (2CO --> C down arrow + CO2) and methanation of CO (CO + 3H(2) --> CH4 + H2O) took place during the reaction on NiO/ZnO catalyst. Contrary to this, the reaction selectively proceeded on MoO3/ZnO even in the presence of a large amount of CO. Mo4+ and Mo5+ species were detected on the catalyst surface. It is deduced that the partially reduced form of supported MoO3 would be effective in improving the selectivity of the reverse water gas shift reaction.