Production of multi-carbon (C₂₊) products via electrochemical CO₂ reduction reaction (CO₂RR) has aroused intensive interest in this decade. However, it is still a great challenge in large-scale synthesis of electrocatalysts for C₂₊ compounds production with high selectivity and rate in neutral electrolyte. In this study, a robust and scalable aqueous synthesis method was proposed to prepare CuO nanosheets, which was directly used as CO₂RR electrocatalyst. The catalyst underwent dynamic restructuring during the pre-reduction stage, which significantly changed the morphology, crystalline structure and electrochemical properties of the catalyst. As a result, the pristine CuO nanosheets gradually evolved to coral-like Cu nanoparticle ensembles (CL-Cu NEs). In 0.1 M KHCO₃ at −1.1 V vs. RHE, the CL-Cu NEs exhibited a faradaic efficiency and partial current density of C₂₊ products of 72.1% and 25.2 mA cm⁻² respectively and no degradation was observed in 15 h running. In contrast to many Cu-based catalysts showing considerable C₂₊ products selectivity, the (sub)surface oxygen and Cu⁺ species were unlikely to play a significant role in this study. The strong performance of CL-Cu NEs was ascribed to the synergism between the coral-like morphology and abundant Cu(1 0 0)/Cu(1 1 1) interfaces. This methodology may provide a cost-effective approach for large-scale preparation of CO₂RR electrocatalysts with ideal nanostructure.

通过电化学CO ₂还原反应（CO ₂ RR）生产多碳（C ₂₊）产品引起了这一十年的浓厚兴趣。然而，在大规模合成用于中性电解质中具有高选择性和速率的C ₂₊化合物生产的电催化剂方面，仍然是一个巨大的挑战。在这项研究中，提出了一种鲁棒且可扩展的水合成方法来制备直接用作CO _2的CuO纳米片。RR电催化剂。催化剂在预还原阶段进行了动态重组，从而显着改变了催化剂的形态，晶体结构和电化学性能。结果，原始的CuO纳米片逐渐演化为珊瑚状的Cu纳米粒子集合体（CL-Cu NEs）。在相对于RHE为-1.1 V的0.1 M KHCO ₃中，CL-Cu NEs的法拉第效率和C ₂₊产物的部分电流密度分别为72.1％和25.2 mA cm ^-2，并且在15 h运行中未观察到降解。与许多显示出相当高的C ₂₊产物选择性的铜基催化剂相比，（亚）表面氧和Cu ⁺物种不太可能在这项研究中发挥重要作用。CL-Cu NEs的强大性能归因于珊瑚状形态与丰富的Cu（1 0 0）/ Cu（1 1 1）界面之间的协同作用。该方法可以为大规模制备具有理想纳米结构的CO ₂ RR电催化剂提供一种经济有效的方法。