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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 BNO_x). The structural evolution from B–C₃ to B–O₃ was well characterized by spectroscopy and soft X-ray absorption techniques. The resulting BNO_x catalysts, enriched with B–O₃ units,more » 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. In conclusion, 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.« less

Transition metal atoms with corresponding nitrogen-coordination (MNx moieties) are widely proposed as catalytic centers for the oxygen reduction reaction (ORR) in metal-nitrogen-carbon (M-N-C) catalysts. Here, an effective strategy that can tailor Fe-N-C catalysts to simultaneously enrich the number of active sites while boost their intrinsic activity and utilization is reported. This is achieved by edge engineering of FeN₄ sites via a simple ammonium chloride salt-assisted approach, where a high fraction of FeN₄ sites are preferentially generated and hosted in a graphene-like porous scaffold. Theoretical calculations demonstrate that the FeN₄ moieties with adjacent pore defects are likely to be more activemore » than the non-defective configuration. Coupled with the facilitated accessibility of active sites, this prepared catalyst when applied in a practical H₂-air proton exchange membrane fuel cell delivers a remarkable peak power density of 0.43 W cm^-2, ranking it as one of the most active M-N-C catalysts reported to date. This work presents a new avenue for boosting ORR activity by edge manipulation of FeN₄ sites.« less