First-Principle Calculations on O-Doped Hexagonal Boron Nitride (H-BN) for Carbon Dioxide (CO) Reduction into C1 Products

With the rapid growth of the world population and economy, the greenhouse effect caused by CO emissions is becoming more and more serious. To achieve the "two-carbon" goal as soon as possible, the carbon dioxide reduction reaction is one of the most promising strategies due to its economic and environmental friendliness. As an analog of graphene, monolayer h-BN is considered to be a potential catalyst. To systematically and theoretically study the effect of O doping on the CO reduction catalytic properties of monolayer h-BN, we have perform a series of first-principle calculations in this paper. The structural analysis demonstrates that O preferentially replaces N, leading to decreasing VBM of monolayer h-BN, which is conducive to improving its capability for CO reduction. The preferential CO adsorption sites on monolayer h-BN before and after O doping are the N-t site and B-t site, respectively. O doping increases the adsorption strength of CO, which is favorable in the further hydrogenation of CO. During the conversion of CO into CO and HCOOH via a two-electron pathway and CHOH and CH via a six-electron pathway, O doping can reduce the energy barrier of the rate determining step (RDS) and change the key steps from uphill reactions to downhill reactions, thus increasing the probability of CO reduction. In conclusion, O(N)-doped h-BN exhibits the excellent CO reduction performance and has the potential to be a promising catalyst.