Design metal-free single-atom catalyst P@BN for CO oxidation: A DFT-D study

Single-atom catalysts (SACs) have arisen significant interest in catalysis and have the superior advantage for CO oxidation. In the current study, beyond the normal single-metal atom catalyst, we designed a new type of metal-free single-atom catalyst based on P doped BN surface. The catalytic mechanism and electronic analysis of CO oxidation on P doped BN metal-free single-atom catalyst is studied by using DFT-D simulation. We found that the phosphorus is preferable to anchor on the boron vacancy of h-BN, and the 3p states of the P dopant would be the key to activate the pre-adsorbed O2. Due to the high catalytic performance and stability of metal-free single-atom, fast charge-transfer kinetics is permissible via catalysis. CO oxidation on the P doped Bv/BN is found to be feasible with the direct formation of CO2 from the cleavage of P–O bonds (ER2 pathway: O2 + CO → CO2 + O) and followed by the reaction process (O + CO → CO2) with low activation energy barriers, indicating that the CO oxidation might be ready at a low temperature. Our work is helpful to reveal the significant role of P dopant for the CO oxidation and shed light on design the new type metal-free single-atom catalyst with low cost, high-performance catalytic activities.