CO2 hydrogenation to methanol over Rh/In2O3–ZrO2 catalyst with improved activity

The InOsupported rhodium catalyst has been previously confirmed to be active for COhydrogenation to methanol. In this work, the InO–ZrOsolid solution was prepared and employed to support the rhodium catalyst. The deposition-precipitation method was applied to make the Rh catalyst highly dispersed. The catalyst characterization confirms that the use of ZrOoptimizes and stabilizes the oxygen vacancies of InO, which causes the enhanced adsorption and activation of CO. The highly dispersed Rh catalyst remarkably improves the hydrogenation ability of the InO–ZrOsupport. Compared to Rh/InO, the InO–ZrOsupported Rh catalyst shows significantly higher activity with high methanol selectivity. For instance, at 300℃ and 5 MPa, the methanol selectivity over Rh/InO–ZrOreaches 66.5% with a space-time yield(STY) of methanol of 0.684 gMeOHhgcatand a COconversion of 18.1%. The methanol selectivity and methanol STY at 300℃ is 19% and 26% higher than that of the Rh/InOcatalyst.