In the present study we demonstrate that the activity and selectivity of SnO₂ nanocatalysts during the aqueous-phase electrochemical reduction CO₂ can be effectively tailored by coupling of nanostructured CuO to form SnO₂CuO nanocomposites. Comparing the Faradaic selectivity of formate as a function of the applied electrode potential and electrolysis time, it is found that CuO incorporation can significantly improve the activity of SnO₂CuO composite catalysts. When the ratio of CuO in the bulk composite was 50%, the formed SnO₂(50%)-CuO(50%) nanocomposite gives the best catalytic performance with the onset potential as early as −0.75 V and the current density at −1.25 V as high as about −24 mA cm⁻². Ion chromatography measurement demonstrates that when the electrolysis was held at −1.0 V for 1 h in 0.5 M KHCO₃, the maximum Faradaic efficiency of formate production can be high up to 74.1%. The outstanding stability of SnO₂ nanocatalyst fabricated electrode is also evidenced due to the stronger synergistic effect induced by CuO compositing, where the SnO₂(50%)-CuO(50%) composite catalyst keeps a steady current density without any dropt over 30 h’ continuous electrolysis approach. The improved performances are deduced from the strong synergistic interactions between SnO₂ and CuO nanocomposite as evidenced from SEM, XRD and XPS analysis results.

在本研究中，我们证明，通过偶联纳米结构化的CuO形成SnO ₂ CuO纳米复合材料，可以有效地定制SnO ₂纳米催化剂在水相电化学还原CO ₂期间的活性和选择性。比较甲酸的法拉第选择性与所施加的电极电势和电解时间的函数，发现掺入CuO可显着提高SnO ₂ CuO复合催化剂的活性。当块状复合材料中的CuO比例为50％时，形成的SnO ₂（50％）-CuO（50％）纳米复合材料具有最佳的催化性能，起始电位为-0.75 V，电流密度为-1.25 V高达约-24 mA cm⁻²。离子色谱法测量表明，当在0.5 M KHCO _3中于-1.0 V下将电解保持1 h时，甲酸生成的最大法拉第效率可高达74.1％。SnO ₂纳米催化剂制成的电极具有出色的稳定性，这归因于CuO复合产生的更强的协同效应，其中SnO ₂（50％）-CuO（50％）复合催化剂保持稳定的电流密度，在30小时内没有任何下降连续电解法。从SEM，XRD和XPS分析结果可以看出，SnO ₂和CuO纳米复合材料之间强的协同相互作用可以提高性能。