Aerobic oxidative desulfurization of liquid fuel catalyzed by P–Mo–V heteropoly acids in the presence of aldehyde

Abstract

Aerobic oxidative desulfurization (ODS) of model liquid fuel (dodecane spiked with diben-zothiophene (DBT)) was carried out in the presence of bulk and supported Keggin-type heteropoly acids H3+nPMo12−nVnO40 (HPA-n, n = 0–3) as heterogeneous catalysts and benzaldehyde as a sacrifi-cial reductant. In the presence of bulk H4PMo11VO40 (HPA-1), 100% of DBT was removed from fuel (converted to DBT sulfone) at 60◦C and ambient air pressure. Multiple catalyst reuse without loss of activity was demonstrated. The ODS reaction was strongly inhibited by radical scavengers. An unbranched radical chain mechanism was proposed.