Boron Nitride Nanofibers as Catalysts for High-Efficiency Aerobic Oxidative Desulfurization

Aerobic oxidative desulfurization (AODS) represents a promising approach to achieving deep desulfurization in petroleum products. Hexagonal boron nitride (hBN) has gained increasing attention as a metal-free catalyst for AODS, offering advantages such as thermal stability, nontoxicity, and environmental friendliness. Despite recent research having highlighted the potential of BN nanocatalysts in AODS, there is a lack of in-depth studies on how micromorphological and structural changes in these BN nanocatalysts influence their AODS performance. In light of this, this paper introduces two distinct 1D BN catalysts, namely, BN nanofibers (BNNFs) and BN microfibers (BNMFs), into the AODS system. The catalysts prepared by using distinct cooling methods exhibit substantial differences in size, micromorphology, pore structure, and defects. Compared to BNMF catalysts, the BNNFs with decreased diameters on the nanometer scale have a hierarchical porous structure and a high percentage of open pore structure on the surface. This unique structural characteristic proved to be more conducive to the efficient transport and diffusion of DBT molecules, significantly enhancing the AODS performance. In addition, the large number of N defects in BNNFs provides abundant active sites for AODS catalysis, thus exhibiting superior AODS catalytic performance in comparison to BNMFs. Furthermore, BNNFs also exhibit efficient removal rates for other sulfur-containing compounds, such as 4-MDBT and 4,6-DMDBT, achieving complete removal (100%) within 6 h. This study highlights the critical role of microstructures in accelerating the AODS process and provides a valuable framework for optimizing the hBN structures for efficient oxidative desulfurization.