Theoretical study of β<sub>12</sub> borophene supported metal for electrocatalytic CO<sub>2</sub> reduction reaction

Abstract

With the increase in global greenhouse gas emissions, reducing CO2 content and effectively utilizing CO2 resources are of great significance. Electrocatalytic carbon dioxide reduction reaction (CO2RR), as a green and sustainable electrochemical method, can convert CO2 into useful chemicals (CO, HCOOH, CH4, CH3OH, etc). Borophene is a promising electrocatalyst due to its excellent physical and chemical properties such as large surface area, good conductivity and flexible electrochemical reaction. Here, a series of TM@beta(12) loaded 3d-TM was designed for electrocatalysis of CO2RR using beta(12) borophene. The Gibbs free energy under the rate-determining step (RDS) is compared by exploring the optimal path of CO2RR, four catalysts with excellent catalytic activity for CO2RR were selected. Among them, Co@beta(12) possess an almost negligible overpotential (0.001 V) for generating CO, which means that CO2 to CO conversion can be realized without additional voltage application. The overpotential of Ti@beta(12), Cu@beta(12) and Zn@beta(12) in the formation of HCOOH products was only 0.02 V. In addition, the overpotential of Ti@beta(12) to CH3OH and CH4 products is very ideal, which are 0.27 and 0.41 V, respectively. As an unexpected surprise, the HER overpotential of Cr@beta(12) was 0.10 V, which is suggested to be an excellent catalyst to replace precious metals for hydrogen production from water electrolysis. This study provides guidance for the rational design and screening of highly active and selective CO2RR catalysts.