Selective Electroreduction of Carbon Dioxide over SnO 2 ‐Nanodot Catalysts

The development of electrochemical CO 2 conversion allows green carbon utilization. Formate and syngas are two typical products of electrochemical CO 2 reduction, and the coproduction of these two products will maximize the energy efficiency of CO 2 conversion. However, few works have successfully achieved the cogeneration of formate and syngas. This paper describes a novel strategy to maximize the efficiency of CO 2 conversion through coproduction of formate and syngas on ultrasmall SnO 2 nanodots (NDs) homogeneously anchored on carbon nanotubes (CNT#SnO 2 NDs) electrodes. The CNT#SnO 2 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#SnO 2 NDs and Ir foil were coupled together to construct an electrolyzer for electrochemical CO 2 reduction reaction and oxygen evolution reaction (CO 2 ERR–OER), which also produced formate and syngas with 24 h stability. A promising approach is presented for the electrochemical CO 2 conversion in fuel production.