The variation in the morphology and electronic structure of copper during the electroreduction of CO₂ into valuable hydrocarbons and alcohols was revealed by combining in situ surface- and bulk-sensitive X-ray spectroscopies with electrochemical scanning electron microscopy. These experiments proved that the electrified interface surface and near-surface are dominated by reduced copper. The selectivity to the formation of the key C–C bond is enhanced at higher cathodic potentials as a consequence of increased copper metallicity. In addition, the reduction of the copper oxide electrode and oxygen loss in the lattice reconstructs the electrode to yield a rougher surface with more uncoordinated sites, which controls the dissociation barrier of water and CO₂. Thus, according to these results, copper oxide species can only be stabilized kinetically under CO₂ reduction reaction conditions.

中文翻译：

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通过将原位X射线光谱和原位电子显微镜相关联，揭示了在电解液中CO2电还原过程中铜的活性相。

通过将原位表面和本体敏感的X射线光谱学与电化学扫描电子显微镜相结合，揭示了在将CO ₂电还原为有价值的烃和醇的过程中，铜的形态和电子结构的变化。这些实验证明，带电的界面表面和近表面以还原铜为主。由于铜金属度的增加，在较高的阴极电位下，形成关键碳原子键的选择性增加。另外，氧化铜电极的减少和晶格中的氧损失使电极重建，从而产生具有更不协调位置的粗糙表面，从而控制了水和CO ₂的解离势垒。因此，根据这些结果，只能在CO ₂还原反应条件下使氧化铜物质动力学稳定。