Highly Active Sm2O3‐Ni Xerogel Catalysts for CO2 Methanation.

We report on a new synthesis route for pure Sm2O3 and Sm2O3‐Ni xerogels by modifying the well‐known epoxide addition method. The resulting xerogels are used to prove the suitability of samaria as a highly effective catalyst support and to determine the optimal Ni loading. Therefore, a set of five catalysts with Ni loadings between 4 wt % and 89 wt % Ni was prepared and fully characterized by X‐ray diffraction, N2 physisorption, transmission electron microscopy and H2 temperature‐programmed reduction. Catalytic measurements reveal that the catalyst with 39 wt % Ni shows the best catalytic performance, outperforming even highly active literature known systems. Stability runs indicate that the catalyst deactivates independently of the Ni loading as well as conversion level over 600 min due to, most likely, carbonate formation. This deactivation, however, is reversible by a simple regeneration step. As shown by simultaneous CO2/CO methanation measurements, the Ni−Sm2O3 catalysts are also highly efficient for CO methanation. In this case, CO is preferentially converted to methane compared to CO2. The good samaria! A new synthesis route for pure and Ni loaded samaria xerogels is reported. The synthesized materials are applied for the hydrogenation of COx to methane. Carefully balancing the Ni loading leads to an optimal ratio of CO2 adsorption and H2 dissociation sites resulting in an exceptional conversion level. Simultaneous CO/CO2 experiments prove the flexibility and high activity of the Ni−Sm2O3 system for various applications. [ABSTRACT FROM AUTHOR]