Understanding the activity phases and reaction mechanisms at the atomic level is essential for the design of electrocatalysts. Herein we investigate the origin of the facet-dependent activity of model CuO catalyst for C-N coupling toward electrocatalytic urea synthesis. It was found that the activity of urea synthesis depends on the crystalline facets of CuO. The CuO (100) facet exhibits higher urea activity and selectivity than the (110) facet, with an average urea yield of 62.4 mmol·g·h at –1.5 V (RHE). By using Raman, UV–vis and XPS techniques, it was observed that Cu serves as active sites at (100) face of CuO, which promotes C-N coupling through synergistic interaction with Cu. Furthermore, the combined results of operando ATR-SEIRAS and DFT calculations demonstrate that the Cu-CuO (100) facet facilitates electrocatalytic C-N coupling between *CO and *NH intermediates due to the reduced energy barriers of hydrogenated *NO on the Cu-CuO (100) facet.

中文翻译：

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识别 Cu2O 的面依赖性活性位点，用于选择性 CN 偶联以实现电催化尿素合成

了解原子水平的活性相和反应机制对于电催化剂的设计至关重要。在此，我们研究了模型 CuO 催化剂用于电催化尿素合成 CN 偶联的晶面依赖性活性的起源。研究发现尿素合成活性取决于 CuO 的晶面。 CuO (100) 晶面比 (110) 晶面表现出更高的尿素活性和选择性，在 –1.5 V (RHE) 下的平均尿素产量为 62.4 mmol·g·h。通过拉曼、紫外可见分光光度和XPS技术，观察到Cu在CuO的(100)面上作为活性位点，通过与Cu的协同相互作用促进CN偶联。此外，操作 ATR-SEIRAS 和 DFT 计算的综合结果表明，由于 Cu-CuO 上氢化 *NO 的能垒降低，Cu-CuO (100) 面有利于 *CO 和 *NH 中间体之间的电催化 CN 偶联。 100) 方面。