In recent years, electrochemical reduction of carbon dioxide (CO₂) has received a great deal of attention due to the potential that this process can mitigate the atmospheric CO₂ concentration and produce valuable organic compounds. In particular, Cu and Cu-based catalysts have exhibited the capability of converting CO₂ into multicarbon fuels and chemicals in significant quantities. Here, we report a facile and cheap fabrication method for the development of an Ag-incorporated cuprous oxide (Ag-Cu₂O) electrode enabling selective synthesis of ethanol via electrochemical CO₂ reduction and reveal the key factor improving the ethanol (C₂H₅OH) selectivity. The incorporation of Ag into Cu₂O leads to the suppression of hydrogen (H₂) evolution, and furthermore, by varying the elemental arrangement (phase-separated and phase-blended) of Ag and Cu, we observe that C₂H₅OH selectivity can be controlled. Consequently, the Faradaic efficiency for C₂H₅OH on phase-blended Ag-Cu₂O (Ag-Cu₂O_PB) is 3 times higher than that of the Cu₂O without Ag dopant. We propose that the electrochemical reaction behavior is not solely associated with a role of Ag dopant, carbon monoxide (CO) leading to an ethanol formation pathway over ethylene, but also the doping pattern related population of Ag-Cu biphasic boundaries relatively suppresses the H₂ evolution reaction and encourages the reaction of mobile CO generated on Ag to a residual intermediate on a Cu site.

中文翻译：

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Ag-Cu两相边界对于选择性电化学还原CO ₂转化为乙醇的重要性

近年来，由于电化学还原二氧化碳（CO ₂）可以减轻大气中CO _2的浓度并产生有价值的有机化合物，因此备受关注。特别地，Cu和Cu基催化剂已经表现出将CO _2大量转化为多碳燃料和化学品的能力。在这里，我们报告了一种易于开发且便宜的制造方法，用于开发结合有银的氧化亚铜（Ag-Cu ₂ O）电极，该电极能够通过电化学CO ₂还原选择性地合成乙醇，并揭示了改善乙醇（C ₂ H ₅OH）的选择性。将Ag掺入Cu ₂ O可以抑制氢（H ₂）的释放，此外，通过改变Ag和Cu的元素排列（相分离和相混合），我们观察到C ₂ H ₅ OH选择性可以控制。因此，法拉第效率对C ₂ H ^ ₅ OH上相共混的Ag-Cu系₂ O（Ag-Cu系₂ ö _PB）比铜的高3倍₂O，不含Ag掺杂剂。我们建议，电化学反应行为不仅与银掺杂剂，一氧化碳（CO）导致乙烯上的乙醇形成途径的作用有关，而且与掺杂模式相关的银铜双相边界总体可相对抑制H _2。生成反应，并鼓励在银上生成的可移动CO与铜位点上的残留中间体发生反应。