The carbon−carbon coupling at the Cu/Cu₂O Schottky interface has been widely recognized as a promising approach for electrocatalytic CO₂ conversion into value-added alcohols. However, the limited selectivity of C₂₊ alcohols persists due to the insufficient control over rectifying interface characteristics required for precise bonding of oxyhydrocarbons. Herein, we present an investigation into the manipulation of the coordination environment of Cu sites through an in-situ electrochemical reconstruction strategy, which indicates that the construction of low-coordinated Cu sites at the Cu/Cu₂O interface facilitates the enhanced rectifying interfaces, and induces asymmetric electronic perturbation and faster electron exchange, thereby boosting C-C coupling and bonding oxyhydrocarbons towards the nucleophilic reaction process of *H₂CCO-CO. Impressively, the low-coordinated Cu sites at the Cu/Cu₂O interface exhibit superior faradic efficiency of 64.15 ± 1.92% and energy efficiency of ~39.32% for C₂₊ alcohols production, while maintaining stability for over 50 h (faradic efficiency >50%, total current density = 200 mA cm⁻²) in a flow-cell electrolyzer. Theoretical calculations, operando synchrotron radiation Fourier transform infrared spectroscopy, and Raman experiments decipher that the low-coordinated Cu sites at the Cu/Cu₂O interface can enhance the coverage of *CO and adsorption of *CH₂CO and CH₂CHO, facilitating the formation of C₂₊ alcohols.

Cu/Cu ₂ O肖特基界面上的碳-碳耦合已被广泛认为是电催化CO ₂转化为增值醇的一种有前途的方法。然而，由于对含氧烃精确键合所需的整流界面特性控制不充分，C ₂₊醇的选择性仍然有限。在此，我们通过原位电化学重构策略对 Cu 位点的配位环境进行了研究，这表明在 Cu/Cu ₂ O 界面上构建低配位 Cu 位点有利于增强整流界面，并诱导不对称电子扰动和更快的电子交换，从而促进CC偶联和键合含氧烃朝向*H ₂ CCO-CO的亲核反应过程。令人印象深刻的是，Cu/Cu ₂ O 界面上的低配位 Cu 位点在 C ₂₊醇生产中表现出优异的法拉第效率（64.15 ± 1.92%）和约 39.32% 的能量效率，同时保持稳定性超过 50 小时（法拉第效率 > 50%，总电流密度= 200 mA cm ^-2 ），在流通池电解槽中。理论计算、原位同步辐射傅里叶变换红外光谱和拉曼实验揭示了Cu/Cu ₂ O界面上的低配位Cu位点可以增强*CO的覆盖以及*CH ₂ CO和CH ₂ CHO的吸附，促进C ₂₊醇的形成。