Enhancing Local CO₂ Adsorption by L‐histidine Incorporation for Selective Formate Production Over the Wide Potential Window

Abstract

Electrochemical carbon dioxide reduction reaction (CO2RR) to produce valuable chemicals is a promising pathway to alleviate the energy crisis and global warming issues. However, simultaneously achieving high Faradaic efficiency (FE) and current densities of CO2RR in a wide potential range remains as a huge challenge for practical implements. Herein, we demonstrate that incorporating bismuth‐based (BH) catalysts with L‐histidine, a common amino acid molecule of proteins, is an effective strategy to overcome the inherent trade‐off between the activity and selectivity. Benefiting from the significantly enhanced CO2 adsorption capability and promoted electron‐rich nature by L‐histidine integrity, the BH catalyst exhibits excellent FEformate in the unprecedented wide potential windows (> 90% within ‐0.1 ~ ‐1.8 V and > 95% within ‐0.2 ~ ‐1.6 V versus reversible hydrogen electrode, RHE). Excellent CO2RR performance can still be achieved under the low‐concentration CO2 feeding (e.g., 20 vol.%). Besides, an extremely low onset potential of ‐0.05 VRHE (close to the theoretical thermodynamic potential of ‐0.02 VRHE) is detected by in situ ultraviolet measurements, together with stable operation over 50 h with preserved FEformate of ~ 95% and a high partial current density of 326.2 mA cm‐2 at ‐1.0 VRHE.