TY - JOUR
T1 - Oxidative desulfurization strategies using Keggin-type polyoxometalate catalysts: biphasic versus solvent-free systems
AU - Ribeiro, Susana O.
AU - Granadeiro, Carlos M.
AU - Almeida, Pedro L.
AU - Pires, João
AU - Capel-Sanchez, Maria C.
AU - Campos-Martin, José M.
AU - Gago, Sandra
AU - de Castro, Baltazar
AU - Balula, Salete S.
N1 - info:eu-repo/grantAgreement/FCT/5876/147218/PT#
info:eu-repo/grantAgreement/FCT/5876/147333/PT#
info:eu-repo/grantAgreement/FCT/5876/147264/PT#
info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBD%2F95571%2F2013/PT#
info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBPD%2F73191%2F2010/PT#
POCI-01-0145-FEDER-007265;
POCI-01-0145-FEDER-007688;
PY - 2019/7/1
Y1 - 2019/7/1
N2 -
Strategic polyoxometalate Keggin-type structural modification was performed to increase the oxidative catalytic performance to desulfurize model and real diesels. The most active lacunar structure [PW
11
O
39
]
7−
(PW
11
) showed to complete desulfurize a simulated diesel after 60 min at 70 °C. Its application as homogeneous catalyst using a biphasic system 1:1 diesel/acetonitrile needed to use an excess of oxidant (ratio H
2
O
2
/S = 8). The immobilization of the PW
11
on amine-functionalized SBA-15 supports originated two heterogeneous catalysts PW
11
@aptesSBA-15 and PW
11
@tbaSBA-15. The best results were attained with the PW
11
@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 (H
2
O
2
/S = 4). The oxidative desulfurization of the real diesel achieved a remarkable 83.4% of efficiency after just 2 h. The recycling capacity of PW
11
@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 PW
11
leaching in the first case. On the other hand, the Venturello peroxocomplex [PO
4
{W(O
2
)
2
}
4
]
3−
, recognized as active intermediate in the homogeneous biphasic system, was not identified in the heterogeneous catalytic systems.
AB -
Strategic polyoxometalate Keggin-type structural modification was performed to increase the oxidative catalytic performance to desulfurize model and real diesels. The most active lacunar structure [PW
11
O
39
]
7−
(PW
11
) showed to complete desulfurize a simulated diesel after 60 min at 70 °C. Its application as homogeneous catalyst using a biphasic system 1:1 diesel/acetonitrile needed to use an excess of oxidant (ratio H
2
O
2
/S = 8). The immobilization of the PW
11
on amine-functionalized SBA-15 supports originated two heterogeneous catalysts PW
11
@aptesSBA-15 and PW
11
@tbaSBA-15. The best results were attained with the PW
11
@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 (H
2
O
2
/S = 4). The oxidative desulfurization of the real diesel achieved a remarkable 83.4% of efficiency after just 2 h. The recycling capacity of PW
11
@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 PW
11
leaching in the first case. On the other hand, the Venturello peroxocomplex [PO
4
{W(O
2
)
2
}
4
]
3−
, recognized as active intermediate in the homogeneous biphasic system, was not identified in the heterogeneous catalytic systems.
KW - Heterogeneous catalysis
KW - Hydrogen peroxide
KW - Oxidative desulfurization
KW - Polyoxotungstates
KW - Real diesel
UR - http://www.scopus.com/inward/record.url?scp=85058412218&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2018.10.046
DO - 10.1016/j.cattod.2018.10.046
M3 - Conference article
AN - SCOPUS:85058412218
SN - 0920-5861
VL - 333
SP - 226
EP - 236
JO - Catalysis Today
JF - Catalysis Today
IS - SI
T2 - 8th World Congress on Oxidation Catalysis on Oxidation Processes - Challenges and Solutions (WCOC)
Y2 - 3 September 2017 through 8 September 2017
ER -