Supported Single Atoms as New Class of Catalysts for Electrochemical Reduction of Carbon Dioxide

Abstract Carbon dioxide (CO 2 ) emitted from excess consumption of fossil fuels leads to the rise of CO 2 concentrations in the atmosphere. One of the most attractive solutions to cut CO 2 emission is the electrochemical reduction of CO 2 to produce fuels and build a low carbon emission economy. However, the electrochemical CO 2 reduction reaction (CO 2 RR) is a great challenge due to the activation of the highly stable, linear CO 2 molecules, and the process involves proton‐coupled multi‐electron transfer with a high energy barrier. Thus, it is critical to develop efficient and highly stable catalyst materials for CO 2 RR. Nanoparticle‐based electrocatalysts have been extensively investigated, but the broad size distribution not only limits their activity due to the size‐dependent catalytic properties, but also constrains the selectivity and leads to undesired side reactions. Single‐atom catalysts (SACs), a rising star in the catalytic area, can combine the merits of heterogeneous and homogeneous catalysts, offering outstanding opportunities for CO 2 RR. The advent of SACs for CO 2 RR has attracted enormous attention recently, and great effort has been devoted into the area and significant advancements have been achieved in recent years. Here, this mini review updates the development of SACs for CO 2 RR, and their opportunities and challenges are discussed.