Oxidative desulfurization of model diesel fuel catalyzed by carbon-supported heteropoly acids

Keggin-type heteropoly acids supported on activated carbon (HPA/C) are active catalysts for oxidative desulfurization (ODS) of diesel fuel under mild conditions in a biphasic system composed of a benzothiophene-containing model diesel fuel (heptane) and aqueous 30% H2O2. The catalytic activity of HPA/C was found to decrease in the order of HPA: H3PMo12O40 > H3PW12O40 > H4SiW12O40. The most active catalyst, H3PMo12O40/C, exhibited 100% removal of benzothiophenes from model diesel fuel at 60 degrees C, and could be recovered and reused without loss of activity. This catalyst outperforms other recently reported heterogeneous catalysts for ODS in similar systems. Kinetic and DRIFTS studies provide new insights into the mechanism of ODS reaction on carbon-supported HPAs.