Study on CO2 hydrogenation to methanol with Pd-In2O3-based catalysts

In recent years, Pd-In2O3 catalysts attracted the research interest for their high selectivity in the hydrogenation of CO2 to methanol, combining the CO2 activation of indium oxide with the hydrogen splitting ability and spillover of palladium. In this work Pd-In2O3-based catalysts with 1%wt. load of Pd were obtained by coprecipitation and tested in a temperature range from 175°C to 300°C, at 30 bar of pressure. Among all the catalysts studied, Pd/In5/Al and Pd/In2O3 achieved high STY (space time yield), particularly at 275°C. Moreover, the influence of the γ-Al2O3 support in Pd/In5/Al granted superior stability over Pd/In2O3, limiting the loss in specific surface area after reaction. Pd/In5/Al catalyst maintained constant methanol productivity of 0.4 gMeOH/(h*gcat) over 100h of reaction, even after being subjected to several start-up and shut-down cycles. Simple economic calculations proved that supporting the active phases on γ-Al2O3 reduced the preparation costs of almost 4 times.