Enhanced CO adsorption and *CO hydrogenation for efficient CO2 deep reduction on MnCu-NC

Abstract

In CO2RR, enhancing CO adsorption could suppress desorption and increase *CO concentration for deep reduction. An underlying concern is that strong adsorption might result in high thermodynamic barrier for *CO hydrogenation, however, kinetic barrier firstly dominates the reaction pathway and determines the products selectivity. Directed by above idea, CO2RR performance on Mn, Cu doped nitrogenated carbon (MnCu-NC) is comprehensively studied using density functional theory (DFT). MnCu-NC shows a mild limiting potential of −0.59 V (*CO → *CHO) for CH3OH and CH4 products. CO poisoning is likely to cause catalyst deactivation, while CO modified MnCu-NC shows a slightly increased limiting potential of −0.63 V (*COCO → *COCHO) for CH3OH and CH4, and hydrogen evolution is significantly suppressed. Further comparative studies indicate that kinetic barrier for *CO hydrogenation is crucial for deep reduction, and C–O activation, as well as CO adsorption is enhanced by Π-backbonding. Besides, introduction Cu to dual-atom catalyst (DAC) could help retain more electrons and Mn has strong magnetization for charge transfer, both of which improve the charge densities and Π-backbonding strength, thus boosting the remarkable CO2RR performance toward CH4 and CH3OH on MnCu-NC.