Deep oxidative desulfurization catalyzed by (NH4)5H6PV8Mo4O40 using molecular oxygen as an oxidant

(NH4)(5)H6PV8Mo4O40 (NPVMo) was evaluated in oxidation desulfurization of dibenzothiophene (DBT), benzothiophene (BT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) in a model oil using O-2 as an oxidant. By controlling the reaction conditions, sulfur contents in the model oil were decreased from 500 ppm to <1 ppm corresponding to DBT, BT and 4, 6-DMDBT with almost 100% yield of sulfone, respectively. Meanwhile, thiophene is one of the main sulfur species in gasoline, which is difficult to be oxidized in conventional oxidative processes and to be removed from fuels. Noteworthily, thiophene was oxidized efficiently at 97% conversion catalyzed by NPVMo and O-2 as oxidant. Such high activity was attributed to the electron transfer between NPVMo and DBT. Meanwhile, NPVMo acted as a heterogeneous and stable catalyst and could be recycled ten times with a slight decrease in activity in the model oil. More importance was that NPVMo was also available for deep desulfurization for FCC gasoline and diesel to obtain almost clear products with extremely lower sulfur content (2.29 and 9.43 ppm, respectively) without formation of by-products of oxidation to loss their octane values. (C) 2017 Elsevier B.V. All rights reserved.