Deep catalytic oxidative desulfurization process catalyzed by TBA-PWFe@NiO@BNT composite material as an efficient and recyclable phase-transfer nanocatalyst

The production of high-quality fuel with substantially lowered sulfur level has attracted a great deal of attention in recent years. Developing high-performance and recyclable catalysts for the desulfurization process remains largely a challenge. In this study, an efficient catalytic oxidative desulfurization (CODS) strategy has been developed using a new phase-transfer nanocatalyst. The TBA-PWFe@NiO@BNT nanocatalyst was fabricated from the mono Fe-substituted phosphotungstate with tetra (n-butyl) ammonium chains (TBA-PWFe), nickel oxide (NiO), and sodium activated bentonite (BNT) for the first time. The TBA-PWFe@NiO@BNT composite was utilized as a recyclable nanocatalyst for the desulfurization of simulated fuels and real gasoline using acetic acid/ hydrogen peroxide (V-CH3COOH/V-H2O2 = 1/2). The best desulfurization results were attained with the TBA-PWFe@NiO@BNT phase-transfer nanocatalyst at 35 degrees C after just 60 min, showing identical CODS performance under mild reaction conditions. The total sulfur removal efficiency of real gasoline achieved a remarkable 98% and the concentration of mercaptans (RSH; R = alkyl group) was reduced from 98 to 3 ppm. On the other hand, thiophenes (Ts), benzothiophenes (BTs), and dibenzothiophenes (DBTs) were near completely removed from the simulated fuels phase with efficiencies of 96, 97, and 99%, respectively. Finally, the recycling capacity of TBA-PWFe@NiO@BNT nanocatalyst was confirmed for five consecutive desulfurization runs without remarkably decreases in its catalytic performance. The overall results obtained have been discussed in detail.

Automated summary

The newly developed TBA-PWFe@NiO@BNT phase-transfer nanocatalyst achieved the best desulfurization results for real gasoline at 35 degrees Celsius after just 60 minutes, with a remarkable 98% sulfur removal efficiency.