The promotion effect of CeO2 on CO2 adsorption and hydrogenation over Ga2O3

Ga2O3 has been confirmed to be an excellent supporting material for CO2 adsorption and conversion. Ga2O3 is also a potential photocatalyst for CO2 conversion. The promotion effect of CeO2 on CO2 adsorption and hydrogenation over Ga2O3 was investigated in this work. The FTIR study and temperature-programmed CO2 desorption (CO2-TPD) confirm that the presence of CeO2 significantly enhances the generation of bicarbonate species during the CO2 adsorption, which is thermodynamically more favored. The bicarbonate species will further react with the dissociatively adsorbed hydrogen on Ga2O3 to generate H2O and CO. The CeO2-promoted Ga2O3 samples thereby show increased activities for reverse water gas shift reaction.

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► The presence of CeO2 make a significant change in CO2 adsorption.
► More bicarbonate species formed during the CO2 adsorption with CeO2/Ga2O3.
► Bicarbonate species reacts with hydrogen on Ga2O3 to generate H2O and CO.
► CeO2 promoted Ga2O3 shows increased activity for reverse water gas shift.