Investigating the catalytic performance of polyoxometalate immobilized on magnetic chitosan in the oxidative desulfurization process

Abstract

In this study, two types of polyoxometalate, one of Keggin type (PMo₆W₆O₄₀) and the other of Dawson type (H₁₁P₂W₁₃V₅O₆₂), were synthesized and fixed on chitosan with magnetic properties. The performance of synthesized catalysts was evaluated on the efficiency of removing aromatic sulfur compounds from the fuel model by the oxidative desulfurization method. Factors affecting the oxidation of sulfur compounds, such as reaction temperature, catalyst dosage, reaction time, and the ratio of oxidant to sulfur, were investigated to find the optimal conditions. The presence of Fe₃O₄ magnetic nanoparticles in the catalyst leads to the ease of separation from the petroleum model. The magnet-separated catalyst could be recycled for 5 catalytic cycles without significantly reducing removal efficiency.