Abstract
Hexagonal boron nitride (h-BN) catalysts exhibit high alkene selectivity in the oxidative dehydrogenation of propane (ODHP). Nevertheless, the conversion-selectivity trade-off persisted primarily due to the low density of oxygen-containing boron active species, while simple and controllable modification strategies for h-BN still face challenges. Herein, we developed an in situ carbon-to-oxygen switch strategy within a tailored boron carbon nitride (BCN) framework, in which uniformly embedded B–C3 were transformed into B–O3 via oxidative treatment (denoted as BNOx). The structural evolution from B–C3 to B–O3 was well characterized by spectroscopy and soft X-ray absorption techniques. The resulting BNOx catalysts, enriched with B–O3 units, demonstrated performance in ODHP, achieving a propane conversion of 50.4% with 32.7% olefin yield at 500 °C. Density functional theory (DFT) calculations confirmed that B–O3 species preferentially lower activation barriers, rendering the process thermodynamically more favorable. This work introduced an in situ reconstruction method for atomic-level heteroatom-engineered h-BN catalysts, opening an avenue for advanced catalyst design across energy conversion systems.
