Electrochemical CO 2 Reduction on a Bi–Sn Eutectic Alloy in Acidic Media for Formic Acid Production

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Electrochemical CO 2 reduction (eCO 2 R) offers a sustainable route for carbon utilization, but most electrolyzers operate in neutral or alkaline media, where (bi)carbonate formation limits long‐term operation and complicates product recovery. Here, we show that operating eCO 2 R under acidic conditions enables direct formic acid production while minimizing (bi)carbonate accumulation. A eutectic Bi–Sn gas‐diffusion electrode (GDE) achieved a faradaic efficiency (FE) of 81.3% toward formic acid at −100 mA cm −2 and in a pH 3 electrolyte, outperforming Bi and Sn GDEs, with formic acid remaining the dominant product up to −400 mA cm −2 . Density functional theory calculations revealed a synergistic Bi–Sn interfacial effect, where weakened hydrogen adsorption and intermediate binding of CO 2 ‐to‐formate intermediates collectively suppress hydrogen evolution and promote formic acid formation. The GDE maintained stable performance with 2 R as a viable strategy for high‐purity formic acid production and demonstrate how interfacial alloy engineering can advance CO 2 electrolysis toward scalable, renewable energy‐powered chemical manufacturing.

This publication has 48 references indexed in Scilit: