TM@MoSSe (TM = Ni, Fe) as novel electrocatalysts for reduction of CO2 to CO: A DFT study

It is crucial to develop highly efficient, selective and low-overpotential electrocatalysts for CO₂ reduction. This paper proposes an efficient iron and nickel single-atom catalyst using Janus MoSSe as the substrate to reduce CO₂ to CO by using DFT calculations. The adsorption of a single TM atom like Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt on Janus MoSSe monolayer results in a decrease in band gap, which may accelerate the catalytic CO₂ reduction. The excellent catalytic activity of Fe@MoSSe and Ni@MoSSe is owing to the high d-band center and hence the strong TM-CO₂ bonding. The asymmetric structure of Janus MoSSe creates the local built-in electric field, which further increases by about 8% or 0.8% after the adsorption of single Ni or Fe atom so as to afford the better electrocatalytic performances for reduction of CO₂ to CO in both TM modified systems. So, this work proposes the catalysts Fe@MoSSe and Ni@MoSSe with good selectivity and activity for CO₂ reduction by revealing their underlying mechanisms, and Janus MoSSe may be used as a potential substrate material for CO₂ reduction catalysts.