The carbon dioxide electroreduction reaction (CO₂RR) provides ways to produce ethanol but its Faradaic efficiency could be further improved, especially in CO₂RR studies reported at a total current density exceeding 10 mA cm⁻². Here we report a class of catalysts that achieve an ethanol Faradaic efficiency of (52 ± 1)% and an ethanol cathodic energy efficiency of 31%. We exploit the fact that suppression of the deoxygenation of the intermediate HOCCH* to ethylene promotes ethanol production, and hence that confinement using capping layers having strong electron-donating ability on active catalysts promotes C–C coupling and increases the reaction energy of HOCCH* deoxygenation. Thus, we have developed an electrocatalyst with confined reaction volume by coating Cu catalysts with nitrogen-doped carbon. Spectroscopy suggests that the strong electron-donating ability and confinement of the nitrogen-doped carbon layers leads to the observed pronounced selectivity towards ethanol.

二氧化碳电还原反应（CO ₂ RR）提供了生产乙醇的方法，但其法拉第效率可进一步提高，特别是在报告的总电流密度超过10 mA cm ^-2的CO ₂ RR研究中。在这里，我们报告了一类催化剂，可实现（52±1）％的乙醇法拉第效率和31％的乙醇阴极能效。我们利用以下事实来抑制中间体HOCCH *向乙烯的脱氧会促进乙醇的生产，因此使用在活性催化剂上具有强电子给体能力的覆盖层进行的封闭会促进CC偶联并增加HOCCH *脱氧的反应能。因此，我们通过用氮掺杂的碳包覆铜催化剂，开发了一种反应体积受限的电催化剂。光谱表明，强的给电子能力和氮掺杂碳层的限制导致观察到的对乙醇的明显选择性。