Phase and structure modulating of bimetallic CuSn nanowires boosts electrocatalytic conversion of CO2

While electrochemical carbon dioxide reduction reaction (CO2RR) is a highly desirable approach for converting CO2 into highly-valued fuels and chemicals, the design and create of efficient CO2 RR catalysts with excellent selectivity to desirable product and long-term stability still remains great challenge. In this work, we have successfully created a series of bimetallic CuSn nanowires (NWs) with modulated phases and structures as superior electrocatalysts for CO2RR. Three distinct CuSn NWs, namely, CuSn NWs/C-Air, CuSn NWs/C-H-2 and CuSn NWs/C-N-2, have been created by the combination of hydrothermal process and controlled thermal treatment in different atmospheres, where the optimized CuSn NWs/C-Air shows significant enhanced activity with the best formate selectivity of 90.2% at -1.0 V versus reversible hydrogen electrode under alkaline condition, which is much higher than those of CuSn NWs/C-H-2 (62.6%) and CuSn NWs/C-N-2 (64.3%). Moreover, the unique CuSn NWs/C-Air also exhibits enhanced stability without significant activity and selectivity degradation after continuous operating about 10 h. Density functional theory calculations reveal that Sn atoms doping into CuO(111) surface, enhancing the adsorption of CO2 intermediate *OCHO and suppressing H-2 production, could be the plausible site to realize the high selective CO2RR observed in CuSn NWs/C-Air. The realization of one-dimensional (1D) heterostructures with precisely modulated phases and structures hold significant promise for the design of efficient electrocatalysts and beyond.