Oxide‐Derived Bismuth as an Efficient Catalyst for Electrochemical Reduction of Flue Gas

Abstract

AbstractPost‐combustion flue gas (mainly containing 5–40% CO2 balanced by N2) accounts for about 60% global CO2 emission. Rational conversion of flue gas into value‐added chemicals is still a formidable challenge. Herein, this work reports a β‐Bi2O3‐derived bismuth (OD‐Bi) catalyst with surface coordinated oxygen for efficient electroreduction of pure CO2, N2, and flue gas. During pure CO2 electroreduction, the maximum Faradaic efficiency (FE) of formate reaches 98.0% and stays above 90% in a broad potential of 600 mV with a long‐term stability of 50 h. Additionally, OD‐Bi achieves an ammonia (NH3) FE of 18.53% and yield rate of 11.5 µg h−1 mgcat−1 in pure N2 atmosphere. Noticeably, in simulated flue gas (15% CO2 balanced by N2 with trace impurities), a maximum formate FE of 97.3% is delivered within a flow cell, meanwhile above 90% formate FEs are obtained in a wide potential range of 700 mV. In‐situ Raman combined with theory calculations reveals that the surface coordinated oxygen species in OD‐Bi can drastically activate CO2 and N2 molecules by selectively favors the adsorption of *OCHO and *NNH intermediates, respectively. This work provides a surface oxygen modulation strategy to develop efficient bismuth‐based electrocatalysts for directly reducing commercially relevant flue gas into valuable chemicals.