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Reverse water gas shift(RWGS) reaction can serve as a pivotal stage in the CO_2 conversion processes,which is vital for the utilization of CO_2.In this study,RWGS reaction was performed over Pt/CeO_2 catalysts at the temperature range of 200-500℃ under ambient pressure.Compared with pure CeO_2,Pt/CeO_2catalysts exhibited superior RWGS activity at lower reaction temperature.Meanwhile,the calculated TOF and E_a values are approximately the same over these Pt/CeO_2 catalysts pretreated under various calcination conditions,indicating that the RWGS reaction is not affected by the morphologies of anchored Pt nanoparticles or the primary crystallinity of CeO_2.TPR and XPS results indicated that the incorporation of Pt promoted the reducibility of CeO_2 support and remarkably increased the content of Ce~(3+) sites on the catalyst surface.Furthermore,the CO TPSR-MS signal under the condition of pure CO_2 flow over Pt/CeO_2catalyst is far lower than that under the condition of adsorbed CO_2 with H_2-assisted flow,revealing that CO_2 molecules adsorbed on Ce~(3+) active sites have difficult in generating CO directly.Meanwhile,the adsorbed CO_2 with the assistance of H_2 can form formate species easily over Ce~(3+) active sites and then decompose into Ce~(3+)-CO species for CO production,which was identified by in-situ FTIR.
Reverse water gas shift (RWGS) reaction can serve as a pivotal stage in the CO_2 conversion processes, which is vital for the utilization of CO_2.In this study, RWGS reaction was performed over Pt / CeO_2 catalysts at the temperature range of 200-500 ℃ under atmospheric pressure. Compared with pure CeO 2, Pt / CeO 2 catalysts superior to RWGS activity at lower reaction temperature. Meanwhile, the calculated TOF and E_a values are approximately the same over these Pt / CeO 2 catalysts pretreated under various calcination conditions, indicating that the RWGS reaction is not affected by the morphologies of anchored Pt nanoparticles or the primary crystallinity of CeO 2 .TPR and XPS results indicated that the incorporation of Pt promoted the reducibility of CeO 2 support and remarkably increased the content of Ce ~ (3+) sites on the catalyst surface.Furthermore, the CO TPSR-MS signal under the condition of pure CO_2 flow over Pt / CeO_2catalyst is far lower than that under the condition of adsorbed CO_2 wi th H_2-assisted flow, revealing that CO_2 molecules adsorbed on Ce ~ (3+) active sites have difficult in generating CO. Mather while, the adsorbed CO_2 with the assistance of H_2 can form formate species easily over Ce ~ (3+) active Sites and then decompose into Ce ~ (3 +) - CO species for CO production, which was identified by in-situ FTIR.