Ga 2 O 3 has been confirmed to be an excellent supporting material for CO 2 adsorption and conversion. Ga 2 O 3 is also a potential photocatalyst for CO 2 conversion. The promotion effect of CeO 2 on CO 2 adsorption and hydrogenation over Ga 2 O 3 was investigated in this work. The FTIR study and temperature-programmed CO 2 desorption (CO 2 -TPD) confirm that the presence of CeO 2 significantly enhances the generation of bicarbonate species during the CO 2 adsorption, which is thermodynamically more favored. The bicarbonate species will further react with the dissociatively adsorbed hydrogen on Ga 2 O 3 to generate H 2 O and CO. The CeO 2 -promoted Ga 2 O 3 samples thereby show increased activities for reverse water gas shift reaction.