A deep-insight into the relation between structure of graphene oxide-based interfacial catalyst and fuel oil desulfurization performance in Pickering emulsion

Based on the high stability, easy demulsification and formed large interphase contact area of the Pickering emulsion, its corresponding catalytic oxidative desulfurization (CODS) system has exhibited satisfactory desulfurization results and recycling performance. However, the relation between the interfacial catalyst structure and desulfurization performance in Pickering emulsion systems has rarely been reported. Herein, a stable Pickering emulsion CODS system was established using H3PW12O40 (HPW)-supported graphene oxide (GO) as an interfacial catalyst. Some important structural parameters, including catalyst size, surface porosities and wettability, were adjusted, and their effect on desulfurization performance was analysed in detail. Additionally, the reaction conditions, selectivity and recyclability of the studied system were systematically evaluated. The small catalyst size and high surface porosities could facilitate mass reaction transfer to improve desulfurization performance, but the effect of wettability was most prominent. The Pickering emulsion formed by the amphiphilic catalyst exhibited the optimum distribution state of emulsion droplets with an enlarged interphase contact area. After the optimized design of the catalyst structure, ultradeep fuel oil desulfurization was achieved under mild conditions without stirring. This work provides a useful reference to further mine the mechanism behind the improvement of desulfurization performance in Pickering emulsion systems.