Synergistic Effect of Cerium Promoter and Dendritic Mesoporous Silica Support on Ni‐Catalyzed CO ₂ Methanation

Abstract Enhancing the dispersion of active metals and tuning their interaction with a suitable support are crucial for improving catalytic performance. Here, we utilize Ce‐promoted dendritic mesoporous silica (Ce‐DMS) as a support that offers abundant oxygen vacancies (O v ) and a high surface area to boost the performance of Ni‐catalysed CO 2 methanation by enriching the Ni–O v –Ce interface and enhancing Ni dispersion. The optimized Ni/5Ce‐DMS catalyst exhibits a high turnover frequency of 1.6 s −1 at 300 °C, which outperformed Ni/DMS and Ni/CeO 2 reference catalysts, as well as other Ni‐based CO 2 methanation catalysts reported in the literature. Combined in situ and ex situ analyses reveal that the superior activity of the Ni/5Ce‐DMS originates from the large specific surface area of the Ce‐DMS support and formation of abundant Ni–O v –Ce interfaces. The oxygen vacancies provided by highly dispersed cerium on the catalyst surface facilitate CO 2 activation, thereby promoting the formation of CH 4 even at low temperatures. Moreover, the numerous silica layers in DMS enhance Ni dispersion and prevent Ni aggregation, thereby achieving enhanced catalytic activity as well as stability.