In Situ Formation of WC/W₂C Heterostructures on N-Doped Carbon for Deep Oxidative Desulfurization of Fuel Oil

A novel tungsten-based heterojunction nanocomposite material was developed for the efficient oxidative desulfurization (ODS) of fuel oil, enabling the production of low-sulfur fuel and a reduction in harmful SO_x emissions. In this material, the WC/W₂C heterojunction was uniformly immobilized on a porous nitrogen-doped carbon (NC) matrix structure through facile in situ pyrolysis of polyaniline-phosphotungstic acid (PANI/PTA) precursors. The resultant WC/W₂C@NC catalyst demonstrated remarkable desulfurization performance, achieving 100% removal of 4000 ppm dibenzothiophene (DBT) in just 15 min at 60 °C in the presence of 0.03 g of WC/W₂C@NC and a H₂O₂/S molar ratio of 2. This exceptional activity is attributed to the synergistic effects stemming from the accelerated electron transfer by the NC matrix, the intricate porous network, and the abundant WC/W₂C heterojunction active sites. Moreover, the in situ formation of NC around WC/W₂C mitigated active site leaching, ensuring remarkable stability, with a DBT removal rate of 97.2% maintained even after eight recycling cycles. This work provides a versatile and scalable approach for fabricating tungsten-based heterojunction catalysts and highlights the potential of WC/W₂C@NC as a high-performance, durable ODS catalyst, paving the way for further advancements in sustainable desulfurization technologies.