Double-Edged Sword Effect of Classical Strong Metal-Support Interaction in Catalysts for CO2 Hydrogenation to CO, Methane, and Methanol

Interesting phenomena such as encapsulation, charge transfer, and bond formation, etc. induced by classical strong metal-support interaction (SMSI) during high-temperature reduction have received wide attention for their potential to determine the catalytic behavior of supported metal catalysts. However, a systematically scientific understanding about the effects of SMSI on CO2 hydrogenation performance is still insufficient primarily due to the diversities in catalysts and reaction conditions. Here, we outline the "double-edged sword effects" of SMSI on the catalytic activity, stability, and even selectivity of hydrogenation of CO2 to C1 high-value compounds (CO, methane, and methanol). Specifically, moderate SMSI could efficiently optimize the structural and electronic properties of catalysts and tune the conversion of key reaction intermediates involved in CO2 hydrogenation, thereby enhancing the catalytic performance. Nevertheless, excessive SMSI is fatal for methanation and methanol synthesis catalysts, because the encapsulation of active centers suppresses the further hydrogenation of reactive intermediates. Additionally, SMSI could alter the CO2 hydrogenation selectivity by regulating the dissociation of H-2 and the breakage of C-O bonds. Subsequently, the structural dependencies of SMSI on supported catalysts are emphasized with the aim of providing guidance for developing CO2 hydrogenation catalysts with an appropriate SMSI by rational design. To conclude, highlighted perspectives on the deeper understanding of SMSI in CO2 hydrogenation catalysts are also presented.