Electrochemical reduction of CO2 to CH4 over transition metal atom embedded antimonene: First-principles study

Abstract

Electrocatalytic CO2 reduction (ECR) represents a promising way for the utilization of renewable energy such as wind and solar to produce value-added fuels or chemicals. The process mainly suffers from the sluggish CO2 reaction kinetics and the lack of efficient electrocatalysts. Herein, we investigated a wide range of transition metal (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Cd, Ir, Pt and Au) atoms anchored into monovacancy of antimonene (Sb monolayer) as single-atom catalysts (SACs) for ECR by first- principles calculation. Interestingly, non-precious TM atoms from the 3d group (TM = Sc, V, Cr, Mn, Fe, Co, Zn) supported on Sb monolayer show higher ECR selectivity than hydrogen evolution reaction selectivity. Moreover, the primary ECR product of these non-precious metal-based SACs is CH4, except for Zn which produces HCOOH. Co@Sb monolayer exhibits the lowest overpotential 0.50 V, which is comparable to reported excellent electrocatalysts. The interaction between TM atom and Sb monolayer greatly affects the intrinsic activity of SACs. Meanwhile, the interaction between TM atoms and intermediates of the potential determining steps (PDS) will determine the overpotential and final products of ECR. This work opens a new family of stable and selective SACs based on antimonene monolayer and provides new insights for screening SACs by charge transfer of bonding atoms.