The mechanism of the reverse water-gas shift reaction over a Cu catalyst wa
s studied by CO2 hydrogenation, temperature-programmed reduction of the Cu
catalyst and pulse reaction with QMS monitoring. In comparison with the rea
ction of CO2 alone, hydrogen can significantly promote the CO formation in
the RWGS reaction. The formate derived from association of H-2 and CO2 is p
roposed to be the key intermediate for CO production. Formate dissociation
mechanism is the major reaction route for CO production. Cu(I) species were
formed from the oxidation of Cu-0 associated with CO2 dissociation.