Ribeiro, SusanaGranadeiro, CarlosAlmeida, Pedro L.Pires, JoãoCapel-Sanchez, Maria C.Campos-Martin, J. M.Gago, S.De Castro, BaltazarBalula, Salete2019-07-192019-07-192019-08-01RIBEIRO, Susana O.; [et al] – Oxidative desulfurization strategies using Keggin-type polyoxometalate catalysts: Biphasic versus solvent-free systems. Catalysis Today. ISSN 0920-5861. Vol. 333, SI (2019), pp. 226-2360920-58611873-4308http://hdl.handle.net/10400.21/10338Strategic polyoxometalate Keggin-type structural modification was performed to increase the oxidative catalytic performance to desulfurize model and real diesels. The most active lacunar structure [PW11O39](7-) (PW11) showed to complete desulfurize a simulated diesel after 60 min at 70 degrees C. Its application as homogeneous catalyst using a biphasic system 1: 1 diesel/acetonitrile needed to use an excess of oxidant (ratio H2O2/S = 8). The immobilization of the PW11 on amine-functionalized SBA-15 supports originated two heterogeneous catalysts PW11@aptesSBA-15 and PW11@tbaSBA-15. The best results were attained with the PW11@aptesSBA-15 catalyst showing identical oxidative desulfurization performance as the homogeneous analogue. As advantage, this heterogeneous catalyst promotes the complete desulfurization of simulated diesel using a solvent-free system, i.e. without the need of acetonitrile use. On the other hand, the same desulfurization efficiency could be achieved using half the amount of oxidant (H2O2/S = 4). The oxidative desulfurization of the real diesel achieved a remarkable 83.4% of efficiency after just 2 h. The recycling capacity of PW11@aptesSBA-15 catalyst was confirmed for eight consecutive cycles using the biphasic and the solvent-free systems. Its stability investigation demonstrates to be higher under the solvent-free system than the biphasic system, without practically any occurrence of PW11 leaching in the first case. On the other hand, the Venturello peroxocomplex [PO4{W(O-2)(2)}(4)](3-), recognized as active intermediate in the homogeneous biphasic system, was not identified in the heterogeneous catalytic systems.engOxidative desulfurizationReal dieselHeterogeneous catalysisPolyoxotungstatesHydrogen peroxidejournal article10.1016/j.cattod.2018.10.046