Polymer JXGZ Modified Bi2O2CO3 Enables Formate Production via Electrocatalytic CO2 Reduction through Synergistic Optimization of Interface and Electronic Structure

Through surface modification of bismuth carbonate (Bi 2 O 2 CO 3 , BOC) using a nitrogen- and oxygen-rich non-ionic polyether (JXGZ), a series of JXGZ-modified BOCs (denoted as x% z-BOC, where z represents the JXGZ modification) were prepared. The interfacial microenvironment and electronic structure of this catalyst were synergistically enhanced, resulting in outstanding performance in the electrocatalytic reduction of carbon dioxide (eCO 2 RR) to form formic acid. Systematic characterization indicates that JXGZ modification significantly enhances the material's hydrophobicity (contact angle increased from 31.5° to 55.1°) and CO 2 adsorption capacity. It stabilizes Bi active sites through electron transfer from oxygen/nitrogen to bismuth, forming an electron-rich surface. Electrochemical testing indicates that 10% z-BOC in a flow cell within 1   M KOH electrolyte can maintain a formate Faraday efficiency exceeding 90% across a broad current density range of −50 to −600   mA   cm −2 . Both its current density and production rate outperform most values reported in the literature. In situ infrared and Raman spectroscopy further confirmed that JXGZ modification not only promotes the formation of the key intermediate *OCHO but also optimizes species supply by regulating the interfacial water structure, while enhancing the structural stability of the Bi−O bond under reaction conditions. This work provides a viable materials strategy for designing high-performance, long-lifetime CO 2 reduction catalysts from the perspectives of electronic regulation and interface engineering.