Extractive-catalytic oxidative desulfurization of a model fuel over vanadium-containing heteropolyacids immobilized on amine-functionalized magnetic graphene oxide: a comparative study between Keggin and Dawson-type heteropolyacids and process optimization via response surface methodology

V-containing HPAs were supported on magnetic graphene oxide and used in an ECODS system. A comparative study between Well–Dawson and Keggin type HPAs in DBT removal was performed. The catalyst was separated easily from the reaction media.