Tuning the CO<sub>2</sub> Hydrogenation Activity via Regulating the Strong Metal–Support Interactions of the Ni/Sm<sub>2</sub>O<sub>3</sub> Catalyst
Jianxiong Zhao, Xiaozhi Liu, Zhengwen Li, Kai Feng, Yue Pan, Pengxiang Ji, Kangning Zhao, Binhang Yan, Dan Zhou, Dong Su
Abstract
Strong metal–support interactions (SMSIs), characterized by the encapsulation of metal nanoparticles by the support oxide, have a significant impact on various heterogeneous catalytic reactions. In this study, we present our investigations on tuning the catalytic performance of CO 2 hydrogenation through regulating the SMSI in a Ni/Sm 2 O 3 catalyst. Our results demonstrate that the complete encapsulation of Ni nanoparticles with amorphous Sm 2 O 3, achieved through H 2 reduction, leads to nearly full selectivity to CO. In contrast, with controlled in situ thermal postannealing in an H 2 /CO 2 /N 2 mixture, the encapsulated Sm 2 O 3 layer can be partially removed and crystallized, as revealed by atomic-resolution transmission electron microscopy analyses, which results in enhanced activity and a full selectivity toward CH 4 . In addition, the prolonged postannealing durations completely remove the Sm 2 O 3 overlayer, causing a decline in CO 2 methanation activity. These findings underscore the critical role of the SMSI effect in CO 2 hydrogenation activity and offer valuable insights for regulating SMSI to produce targeted value-added chemicals.