A comparative DFT study on single-atom catalysis of CO oxidation over Al- and P-embedded hexagonal boron-nitride...

Density functional theory calculations are performed to compare catalytic oxidation of CO molecule over Al- and P-embedded hexagonal boron nitride nanosheet (h-BN). It is found that the Al and P adatom can be stably anchored on the boron-vacancy site of h-BN, as evidenced by a relatively large adsorption energy and charge-transfer value. According to our findings, the oxidation of CO over these surfaces proceeds via the Langmuir-Hinshelwood mechanism, followed by the elimination of the remaining atomic O by another CO molecule. Meanwhile, the stronger adsorption of O₂ than CO avoids poisoning of the active site of both surfaces. The results of the present study indicate that Al-doped h-BN exhibits higher catalytic activity for CO oxidation than P-doped one, which may provide a valuable guidance on design metal-free catalysts to remove toxic CO molecules.