Two iodide-derived copper (ID-Cu) electrocatalysts (E-ID-Cu and W-ID-Cu) are prepared by electrochemical/wet chemical iodination of Cu foil and subsequent in situ electrochemical reduction reaction. In comparison to electropolished Cu (EP-Cu), both E-ID-Cu and W-ID-Cu can produce multicarbon (C₂₊) products with much-improved selectivity, with Faradic efficiency (FE) reaching 64.39% for E-ID-Cu and 71.16% for W-ID-Cu at −1.1 V versus reversible hydrogen electrodes (RHE), which can be attributed to their localized geometry features with high defect density and high surface roughness. Given the well-determined FEs towards C₂₊ products, the partial current densities for C₂₊ production can be estimated to be 251.8 mA cm⁻² for E-ID-Cu and 290.0 mA cm⁻² for W-ID-Cu at −1.2 V versus RHE in a flow cell. In situ characterizations and theoretical calculations reveal that the high-density defects and high surface roughness can promote *CO adsorption by raising the d band center and then facilitate C–C coupling, contributing to the high selectivity of C₂₊ products for ID-Cu. Interestingly, the high surface roughness can increase the residence time of *C–H intermediates and decrease the formation energy of the *OCCO and*CH₃CH₂O intermediates, thus favoring C₂₊ production, with a unique C₂H₆ product observed over W-ID-Cu with FE of 10.14% at −0.7 V versus RHE.

中文翻译：

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局域几何决定了碘化铜对电化学 CO2 还原的选择性

通过铜箔的电化学/湿化学碘化和随后的原位电化学还原反应制备了两种碘化物衍生的铜 (ID-Cu) 电催化剂（E-ID-Cu 和 W-ID-Cu）。与电抛光铜（EP-Cu）相比，E-ID-Cu和W-ID-Cu都可以生产选择性更高的多碳（C ₂₊ ）产品，E-的法拉第效率（FE）达到64.39% ID-Cu 和 W-ID-Cu 在 -1.1 V 时与可逆氢电极 (RHE) 相比为 71.16%，这可归因于它们具有高缺陷密度和高表面粗糙度的局部几何特征。_{鉴于对 C 2+}产品的确定的 FE ，C ₂₊生产的部分电流密度可以估计为 251.8 mA cm ^-2对于 E-ID-Cu 和 290.0 mA cm ^-2对于 W-ID-Cu 在 -1.2 V 与流动池中的 RHE。_{原位表征和理论计算表明，高密度缺陷和高表面粗糙度可以通过提高d带中心促进*CO吸附，然后促进C-C偶联，有助于ID-Cu对C 2+}产物的高选择性. _{有趣的是，高表面粗糙度可以增加*C–H中间体的停留时间并降低*OCCO和*CH 3} CH ₂ O中间体的形成能，从而有利于C _{2+ 的}产生，具有独特的C ₂ H ₆产物在 W-ID-Cu 上观察到，FE 在 -0.7 V 时为 10.14%，相对于 RHE。