Recent advances in single atom catalysts for the electrochemical carbon dioxide reduction reaction

The electrochemical carbon dioxide reduction reaction (CO(2)RR) offers a promising solution to mitigate carbon emission and at the same time generate valuable carbonaceous chemicals/fuels. Single atom catalysts (SACs) are encouraging to catalyze the electrochemical CO(2)RR due to the tunable electronic structure of the central metal atoms, which can regulate the adsorption energy of reactants and reaction intermediates. Moreover, SACs form a bridge between homogeneous and heterogeneous catalysts, providing an ideal platform to explore the reaction mechanism of electrochemical reactions. In this review, we first discuss the strategies for promoting the CO(2)RR performance, including suppression of the hydrogen evolution reaction (HER), generation of C(1) products and formation of C(2+) products. Then, we summarize the recent developments in regulating the structure of SACs toward the CO(2)RR based on the above aspects. Finally, several issues regarding the development of SACs for the CO(2)RR are raised and possible solutions are provided.