The electrochemical CO₂ reduction reaction (CO₂RR) provides a means for producing ethylene, but its selectivity and stability still need further improvement. Therefore, the development of high-performance electrocatalysts is particularly important. Here, we designed a catalyst Cu_xO_y/CN with a nitrogen-doped carbon (CN) coating, which was prepared by pyrolysis of a nitrogen-containing Cu-based MOF with high porosity, using it as a sacrificial template. For the CO₂RR, the Cu_xO_y/CN catalyst demonstrates very good ethylene selectivity, achieving a faradaic efficiency (FE) of 44% at a current density of 500 mA cm⁻². Impressively, the Cu_xO_y/CN catalyst has a higher partial current density for ethylene in the CO₂RR process, reaching about 220 mA cm⁻², compared with other catalysts recorded in the literature. After the CO₂RR, the Cu_xO_y/CN catalyst exposed the Cu(100) facet and the Cu⁺/Cu⁰ interface, which favored the generation of ethylene. Operando Raman spectroscopy indicates that the CN coating efficiently stabilizes Cu⁺ species under CO₂ electroreduction conditions. Density functional theory (DFT) calculations demonstrate that the CN coating stabilizes *CO intermediates. The CN-coated Cu⁺/Cu⁰ interface sites on the Cu_xO_y/CN catalyst enhance *CO adsorption, increase *CO coverage, promote C–C coupling, and thus improve ethylene selectivity and stability.

中文翻译：

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稳定源自金属有机框架的氮掺杂碳涂层 CuxOy 上的 *CO 中间体，用于增强电化学 CO2 制乙烯


电化学 CO₂ 还原反应 （CO₂RR） 提供了一种生产乙烯的方法，但其选择性和稳定性仍需进一步提高。因此，开发高性能电催化剂尤为重要。在这里，我们设计了一种带有氮掺杂碳 （CN） 涂层的催化剂 Cu_xO_y/CN，它是通过热解具有高孔隙率的含氮 Cu 基 MOF 制备的，将其用作牺牲模板。对于 CO₂RR，Cu_xO_y/CN 催化剂表现出非常好的乙烯选择性，在 500 mA ^cm-2 的电流密度下实现了 44% 的法拉第效率 （FE）。令人印象深刻的是，与文献中记录的其他催化剂相比，Cu_xO_y/CN 催化剂在 CO₂RR 工艺中对乙烯的分电流密度更高，达到约 220 mA ^cm-2。在 CO₂RR 之后，Cu_xO_y/CN 催化剂暴露了 Cu（100） 面和 Cu⁺/Cu⁰ 界面，这有利于乙烯的生成。操作符拉曼光谱表明，CN 涂层在 CO₂ 电还原条件下有效稳定 Cu⁺ 物质。密度泛函理论 （DFT） 计算表明，CN 涂层可以稳定 *CO 中间体。 Cu_xO_y/CN 催化剂上 CN 包覆的 Cu⁺/Cu⁰ 界面位点增强了 *CO 吸附，增加了 *CO 覆盖率，促进了 C-C 偶联，从而提高了乙烯的选择性和稳定性。