Synthesis of valuable chemicals from CO₂ electroreduction in acidic media is highly desirable to overcome carbonation. However, suppressing the hydrogen evolution reaction in such proton-rich environments remains a considerable challenge. The current study demonstrates the use of a hollow fiber silver penetration electrode with hierarchical micro/nanostructures to enable CO₂ reduction to CO in strong acids via balanced coordination of CO₂ and K⁺/H⁺ supplies. Correspondingly, a CO faradaic efficiency of 95% is achieved at a partial current density as high as 4.3 A/cm² in a pH = 1 solution of H₂SO₄ and KCl, sustaining 200 h of continuous electrolysis at a current density of 2 A/cm² with over 85% single-pass conversion of CO₂. The experimental results and density functional theory calculations suggest that the controllable CO₂ feeding induced by the hollow fiber penetration configuration primarily coordinate the CO₂/H⁺ balance on Ag active sites in strong acids, favoring CO₂ activation and key intermediate *COOH formation, resulting in enhanced CO formation.

在酸性介质中通过CO ₂电还原合成有价值的化学品对于克服碳酸化是非常必要的。然而，在这种富含质子的环境中抑制析氢反应仍然是一个相当大的挑战。目前的研究表明，使用具有分层微/纳米结构的中空纤维银渗透电极，可以通过CO ₂和K ⁺ /H ⁺供应的平衡协调，在强酸中将CO ₂还原为CO。相应地，在pH = 1的H ₂ SO ₄和KCl溶液中，在高达4.3 A/cm ²的部分电流密度下，以2的电流密度持续电解200 h，CO法拉第效率达到95%。 A/cm ² ，CO ₂单程转化率超过85%。实验结果和密度泛函理论计算表明，中空纤维渗透结构引起的可控CO ₂供给主要协调强酸中Ag活性位点上的CO ₂ /H ⁺平衡，有利于CO ₂活化和关键中间体*COOH的形成，导致CO的形成增加。