Reconstructed PbCO3 with abundant oxygen vacancies for efficient CO2-to-formate electrocatalysis

Abstract

The electrosynthesis of valuable chemical feedstocks and fuels through the CO₂ reduction reaction (CO₂RR) provides a promising approach to solve the global warming problem and the energy crisis. Numerous studies have been devoted to developing electrocatalysts; however, few studies focus on Pb actives sites as well as the defect engineering of active sites. Herein, an O vacancy-rich PbCO₃ electrocatalyst (O-PbCO₃) derived Pb₂(OH)₂(CH₃COO)₂ precatalyst is reported. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) results prove the existence of O vacancies while the X-ray absorption fine structure (XAFS) results reveal the distorted structure of the O-PbCO₃. Electrochemical measurements of the O-PbCO₃ sample exhibit a remarkable selectivity and activity towards formate of over 90% in a wide range of current densities of 50 to 400 mA cm⁻². Further in situ surface-enhanced infrared absorption spectroscopy (SEIRAS) characterization indicates that the O vacancies can optimize the adsorption of the *HCOO intermediate for enhanced CO₂RR performance.