Unlocking the In Situ Reconstruction of Bi/Bi2O2CO3 Electrocatalyst Toward Efficiently Converting CO2 into Formate

Abstract

AbstractElectrochemical reducing CO2 into formic acid has been demonstrated to be an economically viable pathway to relieve the greenhouse effect and obtain value‐added chemical feedstocks. Herein, Bi/Bi2O2CO3 is developed via the combination of sulfur‐assisted disassembly and an in situ reconstruction process. Profiting from the enlarged surface area and the generation of the high active heterointerface between metallic Bi and Bi2O2CO3, the as‐obtained Bi/Bi2O2CO3 exhibits high performance toward converting CO2 molecules into formate (HCOO−), attaining the HCOO− Faradaic efficiency (FEHCOO‐) over 97% in the current density range from 200 to 1000 mA cm−2 in both alkaline (1 m KOH) and near neutral (0.5 m KHCO3) electrolytes, along with excellent stability. In situ spectroscopic data unraveled the reconstruction process from Bi2S3/Bi2O2CO3 to Bi/Bi2O2CO3 and corroborated that the conversion of CO2 into formate is through the *OCHO intermediate, deepening the insights into the understanding of the Bi‐based electrocatalyst reconstruction and CO2RR mechanism.