Copper-based metal-organic framework (Cu-MOF) materials with multiple active sites have attracted increasing attention to the electrocatalytic CO reduction reaction (ECR), however, face the huge challenge owing to the poor stability and low C selectivity. Here, the CuO/Cu-CuTCPP heterojunction (CuO/CPFs) with three Cu active sites are firstly constructed through in-situ electrodeposition method. The effect of CuSO concentration and electrodeposition conditions on ECR is systematically investigated. The optimized CuO/CPFs composite achieves the ethylene Faraday efficiency (FE) of 61.8 % at –1.3 V vs. RHE, which is 1.9 and 3.42 times higher than those of CPFs and CuO, respectively. Meanwhile, the CH partial current density () of –7.96 mA·cm is 2.91 and 4.68 times higher than those of CPFs and CuO. Further experiments reveals that the formation of Cu–O–Cu–O bond between CuO and Cu–O sites in CuO/CPF heterojunction is crucial. Consequently, the hydrogen (H), formic acid (HCOOH) and methane (CH) evolution reactions are restricted, the C–C coupling reaction of *CHO and *CO intermediates is significantly enhanced, and the Cu–O sites in CPFs are protected. This work provides an effective strategy to stabilize MOF structure and obtain high value-added C products.

中文翻译：

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Cu2O/Cu-CuTCPP MOF 异质结的可控制备用于增强电催化 CO2 还原为 C2H4

具有多个活性位点的铜基金属有机骨架（Cu-MOF）材料在电催化CO还原反应（ECR）中受到越来越多的关注，但由于稳定性差和C选择性低而面临巨大的挑战。在这里，首先通过原位电沉积方法构建了具有三个Cu活性位点的CuO/Cu-CuTCPP异质结（CuO/CPF）。系统研究了 CuSO 浓度和电沉积条件对 ECR 的影响。优化的 CuO/CPF 复合材料在 –1.3 V vs. RHE 下实现了 61.8% 的乙烯法拉第效率 (FE)，分别比 CPF 和 CuO 高 1.9 倍和 3.42 倍。同时，CH部分电流密度()为–7.96 mA·cm，分别是CPF和CuO的2.91和4.68倍。进一步的实验表明，CuO/CPF异质结中CuO和Cu-O位点之间Cu-O-Cu-O键的形成至关重要。因此，氢（H）、甲酸（HCOOH）和甲烷（CH）的析出反应受到限制，*CHO和*CO中间体的C-C偶联反应显着增强，并且CPF中的Cu-O位点受到保护。这项工作为稳定MOF结构并获得高附加值的C产品提供了有效的策略。