Hydrogenation of CO2 to methanol over CuCeTiOx catalysts

Abstract

Mixed oxides of CuCeOx, CuTiOx and CuCeTiOx were prepared and evaluated for methanol synthesis via the hydrogenation of CO2. A significant synergistic effect was observed between CeO2 and TiO2 as supports. The CuCeTiOx catalyst was about 4 and 260 times more active than CuTiOx and CuCeOx, respectively, in terms of turnover frequency (TOF) values. The effect of changing the amounts of CeO2, TiO2 and CuO on the catalytic performance of CuCeOx was also studied. With increasing content of CeO2, the CO2 conversion firstly increased and then decreased, with the CeO2/TiO2 weight ratio of 1 being optimal. An increase in the CuO content slightly enhanced the CO2 conversion due to the increase of metal surface area. Kinetic experiments showed that the apparent activation barriers were lower for CO2 activation and methanol synthesis over CuCeTiOx than other Cu-based catalysts.