Selective hydrogenation of CO2 to methanol over Ni/In2O3 catalyst

An In2O3 supported nickel catalyst has been prepared by wet chemical reduction with sodium borohydride (NaBH4) as a reducing agent for selective hydrogenation of carbon dioxide to methanol. Highly dispersed Ni species with intense Ni-In2O3 interaction and enhanced oxygen vacancies have been achieved. The highly dispersed Ni species serve as the active sites for hydrogen activation and hydrogen spillover. Abundant H adatoms are thereby generated for the oxygen vacancy creation on the In2O3 surface. The enhanced surface oxygen vacancies further lead to improved CO2 conversion. As a result, an effective synergy between the active Ni sites and surface oxygen vacancies on In2O3 causes a superior catalytic performance for CO2 hydrogenation with high methanol selectivity. Carbon monoxide is the only by product detected. The formation of methane can be ignored. When the reaction temperature is lower than 225 °C, the selectivity of methanol is 100%. It is higher than 64% at the temperature range between 225 °C and 275 °C. The methanol selectivity is still higher than 54% at 300 °C with a CO2 conversion of 18.47% and a methanol yield of 0.55 gMeOH gcat−1 h−1 (at 5 MPa). The activity of Ni/In2O3 is higher than most of the reported In2O3-based catalysts.