Electrochemical CO₂ reduction to value-added chemical feedstocks is of considerable interest for renewable energy storage and renewable source generation while mitigating CO₂ emissions from human activity. Copper represents an effective catalyst in reducing CO₂ to hydrocarbons or oxygenates, but it is often plagued by a low product selectivity and limited long-term stability. Here we report that copper nanowires with rich surface steps exhibit a remarkably high Faradaic efficiency for C₂H₄ that can be maintained for over 200 hours. Computational studies reveal that these steps are thermodynamically favoured compared with Cu(100) surface under the operating conditions and the stepped surface favours C₂ products by suppressing the C₁ pathway and hydrogen production.

将电化学方法将CO ₂还原为增值化学原料对于可再生能源存储和可再生能源的产生，同时减少人类活动产生的CO ₂排放量具有重大意义。铜代表了一种有效的催化剂，可将CO ₂还原为碳氢化合物或含氧化合物，但铜经常因产品选择性低和长期稳定性受到困扰。在这里，我们报道具有丰富表面台阶的铜纳米线对C ₂ H ₄表现出非常高的法拉第效率，可以维持200小时以上。计算研究表明，与工作条件下的Cu（100）表面相比，这些步骤在热力学上受到青睐，而阶梯表面则对C有利通过抑制C ₁途径和产氢产生_2种产物。