Electrochemical CO reduction reaction (CORR) to HCOOH is one of the most feasible and economical methods to achieve carbon neutrality. Bismuth (Bi), as a metal catalyst for CORR, is considered to have great potential for application and has been widely studied due to its high formate selectivity, low toxicity, cheapness, and abundance. Unfortunately, low current density and short electrode lifetime have hindered its progress towards practical applications. In this work, we present a method that enables the chemical etching of Bi on Cu, which is capable of spontaneously accomplishing the loading of Bi on Cu foam in the liquid phase at room temperature. Additionally, to provide more abundant catalytically active sites, twisted Bi nanowires (BiNWs) with lattice dislocations were successfully prepared on the surface of Cu foam using a three-step chemical method involving oxidation, reduction, and in-situ etching. The Cu Foam@BiNWs was found to be a highly active electrocatalyst for CO reduction to formate at a low applied potential, achieving a faradaic efficiency for formate (FE) of 95 % and a formate partial current density of ∼ 12 mA cm at −0.78 V vs. RHE (reversible hydrogen electrode). Even within such a wide potential window of −0.68 ∼ -1.08 V vs. RHE, the FE is consistently above 90 %. Such exceptional CO reduction activity can be attributed to the distortions and lattice dislocations present in the surface BiNWs. Furthermore, the Cu Foam@BiNWs electrode demonstrated a total current density close to 100 mA cm at −0.98 V in an alkaline flow cell, while maintaining excellent catalytic stability over a prolonged 30-hour period of high current density electrochemical activity, thus showing potential for advancing the industrialisation of formate production. This work emphasizes the crucial role of size-dependent catalysis and crystal defect engineering strategies in the field of electrocatalysis, elucidates the mechanism of the rate-determining step (RDS) in the electrocatalytic CO reduction process on the developed catalysts, which can provide valuable insights into the design and development of high performance electrocatalysts not only in CORR but also in other fields.

中文翻译：

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通过在泡沫铜上原位化学蚀刻形成晶格位错铋纳米线，以增强电催化二氧化碳还原

电化学CO还原反应（CORR）生成HCOOH是实现碳中和的最可行和最经济的方法之一。铋（Bi）作为CO2RR金属催化剂，因其甲酸盐选择性高、毒性低、价格便宜、来源丰富而被认为具有巨大的应用潜力并得到了广泛的研究。不幸的是，低电流密度和短电极寿命阻碍了其实际应用的进展。在这项工作中，我们提出了一种能够在铜上化学蚀刻Bi的方法，该方法能够在室温下在液相中自发地完成Bi在泡沫铜上的负载。此外，为了提供更丰富的催化活性位点，采用氧化、还原和原位蚀刻三步化学方法在泡沫铜表面成功制备了具有晶格位错的扭曲Bi纳米线（BiNW）。 Cu Foam@BiNWs被发现是一种高活性电催化剂，可在低外加电位下将CO还原为甲酸盐，甲酸盐(FE)的法拉第效率为95%，在-0.78时甲酸盐部分电流密度为～12 mA cm V 与 RHE（可逆氢电极）。即使在 -0.68 ∼ -1.08 V vs. RHE 的宽电位窗口内，FE 也始终高于 90%。这种出色的 CO 还原活性可归因于表面 BiNW 中存在的扭曲和晶格位错。此外，Cu Foam@BiNWs电极在碱性流通池中在-0.98 V下表现出接近100 mA cm的总电流密度，同时在长达30小时的高电流密度电化学活性中保持优异的催化稳定性，从而显示出潜在的潜力推进甲酸盐生产工业化。这项工作强调了尺寸依赖性催化和晶体缺陷工程策略在电催化领域的关键作用，阐明了所开发催化剂的电催化CO还原过程中的速率决定步骤（RDS）的机制，可以提供有价值的见解不仅在 CO2RR 领域，而且在其他领域也致力于高性能电催化剂的设计和开发。