Electron structure engineering of MIL-100 via HPMo confinement for advanced oxidative desulfurization catalysis

Efficient oxidative desulfurization (ODS) of aromatic sulfur compounds under mild and green conditions remains a major challenge due to the limited activation ability of molecular oxygen and poor stability of traditional catalysts. In this work, a series of HPMo@MIL-100 catalysts were synthesized for ODS of fuel oils using molecular oxygen as a green oxidant. The introduction of HPMo into the MIL-100 framework not only improved the catalytic performance but also significantly regulated the electronic environment of the Fe active centers. Structural and electronic characterizations confirmed that HPMo incorporation decreased crystallinity, increased surface defects, and facilitated electron transfer within the framework. Detailed experiments identified superoxide radicals as the dominant reactive species, efficiently generated under the synergistic effect of HPMo and MIL-100. The optimized catalyst, HPMo@MIL-100–2, achieved complete removal of aromatic sulfides within 3 h at 120 °C and the aromatic sulfides were selectively conversed to corresponding sulfones. In addition, the catalyst demonstrated excellent recyclability, which can be reused 9 times without significant decrease in ODS performance. Furthermore, a desulfurization efficiency of 95.7 % was achieved to real FCC diesel, highlighting the catalyst’s potential for industrial application. This study provides an effective strategy for tuning MOF catalytic systems through electron modulation, enabling highly efficient, selective, and recyclable ODS performance under mild conditions.