Rational design of the carbon doping of hexagonal boron nitride for oxygen activation and oxidative desulfurization

Abstract

The doping of hexagonal boron nitride (h-BN) materials has a great influence on their catalytic oxidation performance, but the mechanism of doping has still not been studied in depth to date. Herein, carbon-doped h-BN materials were systematically investigated. Three different doping modes were established, and their performance for O₂ activation and oxidative desulfurization (ODS) were explored. DFT calculation showed that not all carbon-doped forms of the h-BN surface could activate O₂. Specifically, two of the dispersed doping forms could activate O₂, whereas the π-doping form could not activate O₂, and thus the ODS reaction could not be carried out. For the two dispersed doping forms, the O₂ adsorption on the C_B-doped h-BN surface (C-doped in B position) was too strong, which hampered its ODS performance; whereas the O₂ adsorption on the C_N-doped h-BN surface (C-doped in the N position) was moderate, resulting in good catalytic activity for ODS. Therefore, to design effective BN-based catalysts by C doping, it is suggested that the C dopant should be dispersed to substitute the N atom of h-BN, and C_N-doped h-BN will play an important role in ODS with moderate O₂ activation. This study can be used as a reference for the catalytic oxidation of boron nitride.