Latest Approach to Fuel Desulfurization Using Polyoxometalate Catalyst Modified Halloysite Nanotubes Optimized by Surface Response Methodology

Abstract

A novel catalyst termed K6P2W18O62·nH2O@fHNTs was synthesized and optimized for the photo-oxidative desulphurization of model fuel oil. Halloysite nanotubes (HNTs) were subject to functionalization with 3-aminopropyltriethoxysilane (APTES) and subsequently utilized as a substrate to immobilize K6P2W18O62·nH2O. FTIR, XRD, and SEM analysis confirm the electrostatic interaction between K6P2W18O62·nH2O and the functionalized halloysite nanotubes. Photo-oxidative desulphurization process was conducted using light as an energy source, acetonitrile as the extracting agent and H2O2 as an oxidant. The optimization of reaction variables, including reaction time (15-45 min), temperature (40-70 °C), and catalyst dosage (0.05-0.1 g) using the Box-Bhenken method. The optimal conditions were determined to be 70°C, 0.1 g, and 30 min, resulting in a desulfurization efficiency of 91.51%. The catalyst exhibited excellent recyclability, maintaining a stable desulphurization rate over seven consecutive cycles. This research highlights the potential of K6P2W18O62·nH2O@fHNTs as an effective and reproducible catalyst for the process of photo-oxidative degradation of sulfur, offering promise for the development of cleaner and more sustainable fuel technologies.