Recent Advances in Polyoxometalate@Porous-Framework Composite Catalysts for Oxidative Desulfurization

Driven by the escalating global emphasis on green chemistry and sustainable development, the deep desulfurization of fossil fuels has emerged as a critical research frontier. Among various techniques, oxidative desulfurization (ODS) has garnered significant attention as a mild and efficient alternative to traditional hydrodesulfurization. Polyoxometalates (POMs) have been widely proven to exhibit excellent catalytic performance in ODS reaction due to their tunable electronic structure, abundant active-sites, and unique redox properties. However, the intrinsic solubility of POMs in polar media leads to challenges in catalyst recovery and recycling. To address these bottlenecks, the heterogenization of POMs via encapsulation within porous architectures has become a highly active research area. This strategy not only prevents the leaching, aggregation, and deactivation of POMs but also leverages the high surface area and pore environments to enhance mass transfer and substrate accessibility. This review will systematically summarize the POMs encapsulated in three typical porous supports, including inorganic mesoporous zeolites, organic porous frameworks, and organic-inorganic hybrid frameworks. By analyzing the synergistic effects between the POMs and the porous frameworks, this work will highlight how structural design influences catalytic efficiency and stability. Finally, we offer perspectives on the future challenges and design principles for developing high-performance ODS catalysts.