Mesoporous Ni–CeO₂ Catalyst with Enhanced Selectivity and Stability for Reverse Water–Gas Shift Reaction

Abstract

Mesoporous Ni–CeO₂ catalyst was prepared by a polymer (P123)-assisted co-precipitation method and used for reverse water–gas shift reaction. Compared with the catalysts prepared by traditional co-precipitation methods, the mesoporous Ni–CeO₂ catalyst shows higher stability for the reverse water–gas shift reaction at 600°C but with no formation of the side product CH₄. Moreover the mesoporous Ni–CeO₂ catalyst is also highly active for reverse water–gas shift reaction. TPR and XRD results suggest that, in the mesoporous Ni–CeO₂ catalyst, Ni²⁺ ions are incorporated into the CeO₂ lattice to form a Ni_xCe_yO₂ solid solution, which produces a large number of oxygen vacancies and enhances the reducibility of the surface CeO₂. The excellent performance of the mesoporous catalyst is related to the lack of exposed NiO particle on the surface, and the large amount of oxygen vacancies in the uniform mesoporous structure.