Experimental and theoretical studies of CO2 hydrogenation to methanol on Ru/In2O3

Abstract

Ruthenium catalyst was extensively employed for homogeneous and heterogeneous CO2 conversion. However, only a few works can be found with Ru catalysts for heterogeneous CO2 hydrogenation to methanol. The activity of these reported Ru catalysts is not high. In this work, we prepared the Ru/In2O3 catalyst by deposition-precipitation. The obtained catalyst shows high dispersion and high activity for CO2 hydrogenation to methanol with high methanol selectivity (97.4 % at 200 °C and 69.7 % at 300 °C). The methanol space-time yield reaches 0.57 gmethanol gcat−1 h−1 at 300 °C, 67.6 % higher than that of In2O3. The Ru loading causes a strong hydrogen spillover effect, which further promotes the formation of oxygen vacancies on In2O3. The enhanced ability for activation of hydrogen and CO2 on Ru/In2O3 catalyst causes the high activity in CO2 hydrogenation. The theoretical study reveals that the CO-hydrogenation route is thermodynamically most favored for CO2 hydrogenation to methanol on Ru/In2O3.