Bismuth oxycarbonates loaded on nitrogen-doped carbon: an efficient nanocomposite catalyst for electrochemical reduction of CO2 to formate

Abstract

The consumption of fossil fuels has led to a significant increase in CO₂ in the atmosphere, resulting in the greenhouse effect and placing tremendous pressure on the global environment. The electrocatalytic reduction of CO₂ to produce the high-value chemical formic acid or formate is an efficient and environmentally friendly method with significant practical implications for achieving carbon neutrality. This study presents a nanocomposite catalyst of bismuth oxycarbonate loaded on nitrogen-doped carbon materials (BOC-NC), prepared using a hydrothermal method. In an H-type electrolytic cell, the BOC-NC-900 °C catalyst exhibited excellent electrochemical CO₂ reduction (CO₂RR) performance, achieving a faradaic efficiency of 94.9% for formate production and maintaining catalytic stability over 38 h of the CO₂RR at −1.0 V vs. RHE, while in a flow-cell configuration, it achieved a current density of 91 mA cm⁻², a faradaic efficiency of 90.5% for the formate, and sustained stability over 10 hours at −1.0 V vs. RHE. The synergistic effect generated between BOC and NC enhances the formate selectivity, providing valuable insights for developing composite materials that integrate bismuth-based catalysts with carbon matrices.