Selective electroreduction of CO2 to ethanol over a highly stable catalyst derived from polyaniline/CuBi2O4

Abstract

Electroreduction of CO₂ to ethanol with high stability and selectivity is vital for resourceful CO₂ utilization. The catalyst derived from PANi/CuBi₂O₄via an electrochemical activation process shows high faraday efficiency (FE) for the electroreduction of CO₂ to ethanol (∼64.15%). Repeated redox reaction generated the evolutionary surface of PANi/CuBi₂O₄ with Cu⁰⁺ and Bi⁰⁺ crossed. Owing to the high priority of the adsorbed O-terminal on the introduced Bi, which is located on the Cu surface, the CO₂RR pathway for ethylene is suppressed after C–C coupling, making PANi/CuBi₂O₄ more likely to produce ethanol. With our thorough investigation of the PANi/CuBi₂O₄ composite system, the agglomerate behaviour of the catalyst in the activation process can be effectively suppressed leading to the high stability and long lifetime of the catalyst. Our findings highlight the importance of local surface evolution by electrochemical pretreatment while retaining the excellent property by stabilizing the main body of the catalyst.