Selective Electroreduction of Carbon Dioxide over SnO2-Nanodot Catalysts

The development of electrochemical CO2 conversion allows green carbon utilization. Formate and syngas are two typical products of electrochemical CO2 reduction, and the coproduction of these two products will maximize the energy efficiency of CO2 conversion. However, few works have successfully achieved the cogeneration of formate and syngas. This paper describes a novel strategy to maximize the efficiency of CO2 conversion through coproduction of formate and syngas on ultrasmall SnO2 nanodots (NDs) homogeneously anchored on carbon nanotubes (CNT#SnO2 NDs) electrodes. The CNT#SnO2 NDs not only decreased the adsorption energy of *OCHO but also reduced the adsorption energy difference of *COOH and *H. High energy efficiency toward formate and adjustable H-2/CO ratio were obtained over a broad potential window with long-term stability. In addition, CNT#SnO2 NDs and Ir foil were coupled together to construct an electrolyzer for electrochemical CO2 reduction reaction and oxygen evolution reaction (CO2ERR-OER), which also produced formate and syngas with 24 h stability. A promising approach is presented for the electrochemical CO2 conversion in fuel production.