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

Abstract

Electrochemical carbon dioxide reduction reaction (CO₂ RR) 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 CO₂ RR 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 FE_formate 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 CO₂ RR performance can still be achieved under the low-concentration CO₂ feeding (e.g., 20 vol.%). Besides, an extremely low onset potential of -0.05 V_RHE (close to the theoretical thermodynamic potential of -0.02 V_RHE ) was detected by in situ ultraviolet-visible (UV-Vis) measurements, together with stable operation over 50 h with preserved FE_formate of ≈95 % and high partial current density of 326.2 mA cm^-2 at -1.0 V_RHE .