Reaction mechanism of metal-free borophene catalyst electrochemical reduction of CO2

Abstract

The utilization of electricity generated from renewable energy sources for carbon dioxide reduction reaction (CO2RR) to produce high-value chemical resources is of significant importance for reducing CO2 emissions and for energy storage. However, the search for environmentally friendly and efficient metal-free catalysts to facilitate CO2 conversion continues to present numerous challenges. This study employs density functional theory (DFT) calculation to explore the potential of two-dimensional metal-free borophene catalysts in the activation and conversion of CO2. Through molecular dynamics simulations, energy band and density of states analysis, the stability and electronic properties of metal-free borophene were thoroughly examined. The calculations demonstrated that two specific sites on electron-deficient zigzag borophene possess strong adsorption capabilities for CO2, enabling effective activation of CO2. Further investigation revealed that the reduction of CO2 at site 1 on zigzag borophene efficiently produces CO, HCOOH, CH3OH, and CH4, with the potential determining steps (PDS) requiring overpotentials of 0.11 V, 0.20 V, 0.38 V, and 0.52 V, respectively. In summary, this research provides theoretical foundation for the use of metal-free borophene as an efficient catalyst for CO2RR.