Revealing the Support Effect of Nickel-Based Catalysts Toward CO2 Methanation

Understanding the role of support is of guiding significance for studying the structure–activity relationship of supported Ni-based catalysts. In this work, catalysts with 0.1, 1, and 10 wt.% of NiO supported on CeO 2 , ZrO 2 , TiO 2 , and Al 2 O 3 were prepared by the impregnation method. The catalytic performance of CO 2 methanation was correlated with Ni particle size, reducibility, and basicity. The activity of the catalyst was found to be positively correlated with both the Ni particle size and reducibility, which promote the hydrogen dissociation and CO 2 activation processes, respectively. However, the basicity of the catalyst does not seem to be related to the reaction activity. Moreover, the coexistence of formate and the associative mechanism over the catalysts was evidenced. Graphical This work reveals that in CO 2 methanation over supported Ni catalysts, catalytic activity correlates positively with Ni particle size and reducibility, enhancing H 2 dissociation and CO 2 activation, respectively, but not with basicity. The coexistence of formate and associative mechanisms is confirmed over nickel-based catalysts in this work.