Deep desulfurization of real fuel oils over tin-impregnated graphene oxide-hydrogen peroxide and formic acid catalyst-oxidant system

Abstract

Herein, Tin-impregnated graphene oxide (Sn/GO) composite was designed and tested for the catalytic removal of sulfides from the simulated and real commercial oils in the hydrogen peroxide and formic acid (HCOOH/H2O2) oxidation system. The prepared GO and Sn/GO were characterized in terms of surface morphology and other catalytic properties, which confirmed that the Sn/GO catalyst has a large surface area and more surface functional groups than GO. The desulfurization activity of the Sn/GO-HCOOH/H2O2 system was analyzed for the model dibenzothiophene (DBT) and real commercial oil at different substrate concentrations, time, temperature, pH, and oxidant and catalyst doses. The results showed that the Sn/GO-HCOOH/H2O2 system removed 97% DBT from the model oil and accumulative sulfur of 90%, 69%, and 61%, respectively, from gasoline, diesel, and kerosene oil employing 0.03 g/10 mL catalyst, 2 mL of H2O2/HCOOH in 50 min at 50°C, and pH 3. Sn/GO could be recycled up to five consecutive runs retaining more than 57% efficiency. Due to its environmental greenness, ease of preparation, and cost-effectiveness, this unique catalyst-oxidant system can be envisioned for the oxidation of sulfides from real oils. Research Highlights Pristine and Sn-loaded GO composite were synthesized and characterized. The Sn/GO-HCOOH/H2O2 system oxidized 97 and 90 % DBT from the model and real oil. O2− radicals generated due to synergism between Sn/GO and HCOOH/H2O2 species. The Sn/GO-HCOOH/H2O2 system remained active for five successive reuses.