Jinpei Hei

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.

CO₂ hydrogenation to methanol was conducted using a set of activated carbon-supported Cu/ZnO/Al₂O₃ catalysts (CCZA) prepared by an incipient wetness impregnation approach. The effect of the Cu/Al ratio on the physicochemical properties of the catalysts, as well as their catalytic performance, were investigated. As Cu/Al ratio increased, the metallic Cu surface area displayed a reducing trend from 6.88 to 4.18 m²∙g_cat⁻¹, while the CO₂ adsorption capacity exhibited an increasing trend. Meanwhile, aluminum content will have an important effect on the catalysts’ reducibility and, thus, on their catalytic performance. The CCZA-2.7-de catalyst demonstrated the highest selectivity to methanol at 83.75% due to the excellent distribution and synergistic effect of copper and zinc. Although the CO₂ conversion of CCZA-2.2-de and CCZA-3.5-de exceeded 10%, the CH₃OH selectivity was less than 60%, which may be attributed to the larger particle sizes of ZnO and poor interactions in Cu–Zn. The present study offers a novel approach to increase the number of active sites, optimize the activated carbon-aided Cu/ZnO/Al₂O₃ catalyst’s composition, and finally elucidate the mechanism for CO₂ hydrogenation to methanol.