Using Immobilized Hybrid Composites Based on Mixed Polyoxometalates As Catalysts for the Oxidation of Heteroatomic Compounds

A set of silica gel-immobilized compounds is synthesized that consists of ethylimidazole cations and anions of phosphotungstic acid (lacunar (PW 11 ) or mixed (PW 11 M), where M = Zn, Ni, Cu, Co, Mn). The composition and textural characteristics of the compounds are determined by physicochemical means (IR spectroscopy, XPS, SEM/EDX, adsorption). The synthesized heterogeneous composites are active in the oxidation of sulfur- and nitrogen-containing components of petroleum feedstocks with hydrogen peroxide. A comparative analysis is performed of the samples’ catalytic properties in the oxidation of both individual substrates (thiophene, dibenzothiophene, methyl phenyl sulfide, pyridine) and their mixtures.