| Abstrakt: |
Aimed at catalytic oxidative desulfurization (cat-ODS) of sulfur-containing aromatic compounds (SAs) and catalytic oxidative denitrogenation (cat-ODN) of nitrogen-containing aromatic components (NAs) to control air pollution, we successfully designed and synthesized a new green catalyst (named as TBAPMo11Cu@CuO) based on quaternary ammonium salt of copperII-monosubstituted phosphomolybdate [(n-C4H9)4N][PMo11CuO39] (TBAPMo11Cu) and copper oxide (CuO) via a sol–gel method. Cat-ODS and cat-ODN processes of SAs (thiophene (Th) and dibenzothiophene (DBT)), NAs (pyridine (Py) and carbazole (CBZ)) were carried out using hydrogen peroxide green oxidant and poly(ethylene glycol) (PEG-200), which is considered as a green extractant over a TBAPMo11Cu@CuO catalyst. This new catalyst demonstrated a superb catalytic activity in the oxidation of SAs and NAs and long-term stability for producing ultraclean fuels: 97, 98, 99, and 98% values of conversion were obtained for Th, DBT, Py, and CBZ, respectively, at 35 °C. The results proved that Th and DBT were converted to the corresponding sulfoxides and sulfones, while Py and CBZ were oxidized to the corresponding N-oxides. Accordingly, the oxidized product of CBZ was identified as carbazole-9-carbaldehyde. Also, the removal of a considerable amount of Th, DBT, Py, and CBZ is possible via catalytic oxidation–extraction; however, simple solvent extraction (using methanol, ethanol, and acetonitrile) was inadequate for deep denitrogenation and desulfurization. TBAPMo11Cu@CuO as a catalyst indicated excellent reusability for five oxidation cycles. The high performance of TBAPMo11Cu@CuO/H2O2/PEG-200 can prove it as a promising green method for fuel purification. |
