Engineering Acidic CO 2 Electroreduction for Efficient and Durable Formic Acid Production

Abstract

Electrochemical synthesis of formic acid (HCOOH) via the carbon dioxide reduction reaction (CO 2 RR) in acidic electrolytes can circumvent the severe CO 2 loss in alkaline and neutral conditions. However, simultaneously attaining high HCOOH production efficiency and durable long‐term operation in acidic CO 2 RR remains a critical bottleneck impeding the technology's practical deployment. Herein, we first discuss the core challenges faced by acidic CO 2 RR to HCOOH, most notably the competing hydrogen evolution reaction, serious catalyst deactivation, and the inherent trade‐off between product selectivity and carbon utilization efficiency. Then, key strategies to improve CO 2 to HCOOH conversion efficiency are systematically summarized, with a focus on stabilization of key reaction intermediates and rational engineering of the catalytic microenvironment. Additionally, effective approaches to enhance catalyst durability, as well as the design of advanced electrolyzer configurations tailored for acidic CO 2 RR systems, are elaborated. We end the review by outlining the existing challenges and future directions for accelerating the industrialization of acidic CO 2 RR to HCOOH.