Selective HCOOH Production over Wide Potential Range via Defective Oxide-Derived Bismuth

Electrochemical reduction of CO2 toward value-added liquid fuel is a promising route to achieve the carbon neutrality. Especially for CO2 electroreduction to formic acid production, despite the favorable activity and selectivity can be achieved, unstable Faradaic efficiency (FE) in wide potential range and poor energy efficiency remain the bottlenecks. Herein, this study reports a metallic Bi catalyst (B-ArH2-2) derived from defective Bi2O3, which achieves nearly 100% FE for HCOOH production over a broad potential range (-0.7 to -1.1 V) with an outstanding cathodic energy efficiency of 71%. Additionally, B-ArH2-2 displays a high partial current density of HCOOH (j(HCOOH), 27.5 mA cm(-2)) and production rate (475 mu mol h(-1) cm(-2)) with favorable long-term stability (20 h).

Automated summary

In the field of electrochemical reduction of CO2 for liquid fuel production, the unstable Faradaic efficiency and poor energy efficiency are major challenges. This study introduces a metallic Bi catalyst (B-ArH2-2) derived from defective Bi2O3, which achieves high formic acid production rate and excellent cathodic energy efficiency over a wide potential range, as well as demonstrating good long-term stability.