Enhanced oxidative desulfurization in a film-shear reactor

•A film-shear reactor was used to enhance oxidative desulfurization (ODS).•Recalcitrant thiophenes are oxidized within seconds to sulfones in the reactor.•Desulfurization using hydrogen peroxide occurs within seconds at high flow rates.•Molecular thermometers showed the absence of thermal hot spots in the reactor.•The fast ODS reaction is attributed to superb mixing of the nonmiscible phases.