Mechanism of the reverse water gas shift reaction over Cu/ZnO catalyst

The reverse water gas shift reaction (RWGS) and the reaction with CO 2 alone were carried out over a Cu/ZnO catalyst. The surface of the catalyst was characterized by N 2O titration, XPS, and FT-IR spectroscopy. CO 2 dissociated to give CO and the surface oxygen species. Surface Cu(I) oxide was formed by the reaction with CO 2. The oxygen species were hydrogenated to H 2O and the surface Cu(I) oxide was reduced to metallic Cu. It is suggested that the RWGS reaction proceeds through surface oxidation and reduction with CO 2 and H 2, and the dissociation of CO 2 is the rate determining step.