Electrolyte Flow-Driven Coupling of Oxygen Evolution Reaction and CO 2 Electroreduction for Promoting Selective HCOOH Production under Acidic Conditions

作者：Shanshan Wu, Xiangyang Yin, Zhihao Liu, Weifeng Zhang, Yongkui Huang, Fan Dong, Daijun Zhang · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.5c00707 · 被引用次数：7 · 研究领域：CO2 Reduction Techniques and Catalysts、Electrocatalysts for Energy Conversion、Ionic liquids properties and applications

The electrocatalytic CO 2 reduction reaction (ECO 2 RR) toward liquid fuels is one of the most promising routes to sustainable carbon neutrality. However, reducing energy consumption and improving product selectivity of the ECO 2 RR in acidic environments remain challenging. To address these issues, we propose a novel process by coupling the oxygen evolution reaction (OER) and ECO 2 RR using an anode-to-cathode electrolyte flow to enhance formic acid (HCOOH) production under acidic conditions. The coupling process achieves an outstanding Faradaic efficiency (FE) of 95.9% for HCOOH production, reduces cathodic energy consumption by 19.5% compared with the traditional ECO 2 RR, and exhibits superior stability with FE HCOOH > 80% for over 80 h at 200 mA cm –2 . Dissolved oxygen is activated on the Bi-Bi 2 O 2 CO 3 @CNTs cathode to produce *OOH, lowering the activation energy barrier of CO 2 and facilitating the formation of key intermediates (*OCHO) for HCOOH production. Furthermore, the coupling process can modulate the local interfacial electric field to promote the activation of CO 2 in the acidic electrolyte. Dissolved oxygen facilitates the Bi/Bi δ+ redox cycle to provide active sites for the conversion of CO 2 to HCOOH during long-term electrolysis. This study provides a proof-of-concept demonstration of the ECO 2 RR/OER coupling process, making CO 2 electroreduction more energy-efficient and economical.