Ga and Ti co-doped CeO2 nanorod catalysts with enhanced activity towards the synthesis of dimethyl carbonate from CO2 and methanol

Abstract

Novel Ga and Ti co-doped CeO₂ nanorod catalysts were synthesized using a one-pot hydrothermal process and characterized by XRD, TEM, FT-IR, Raman, N₂ adsorption–desorption, CO₂-TPD, NH₃-TPD, H₂-TPR and XPS techniques. Their catalytic properties were investigated in the synthesis of dimethyl carbonate (DMC) from methanol and CO₂. Results showed that the addition of a small amount of Ti and Ga into CeO₂ obviously enhanced the catalytic activity in the DMC formation from methanol and CO₂. Among the series of Ga doped CeO₂ catalysts, the Ce₁Ga_0.2Ti_0.02 catalyst exhibited the best catalytic performance and the yield of DMC was as high as 24.6 mmol_DMC g_cat⁻¹ after 2 hours of reaction time, outperforming all reported catalysts without a dehydrating agent. The enhanced catalytic activity of the Ce₁Ga_0.2Ti_0.02 catalyst is attributed to more surface oxygen vacancies and acid–base sites, favoring the activation of methanol and CO₂ and further forming intermediate species and promoting DMC generation. This work provides two-element co-doped metal oxide catalysts for efficient conversion of CO₂ to DMC.