Catalytically active coatings on titanium were synthesized by plasma electrolytic oxidation (PEO) in aqueous electrolytes containing sodium phosphate and tungstate, as well as iron chelate complexes with EDTA. Analysis of EDX, XPS and XRD data allowed concluding that the PEO coatings contain titanium dioxide and amorphous tungstates and/or phosphates of iron. High phosphorus concentrations (up to 6 at. %) promoted amorphization. Testing the PEO catalysts showed their activity in oxidative desulfurization (ODS) of thiophene and dibenzothiophene with hydrogen peroxide and air oxygen.
I. G. Tarkhanova (Wed,) studied this question.