7 documents found, page 1 of 1
Dichloro and dimethyl dioxomolybdenum(VI)-bipyridine complexes as catalysts for...
Julião, Diana; Gomes, Ana C.; Cunha-Silva, Luís; Pillinger, Martyn; Gonçalves, Isabel S.; Balula, Salete S.The complexes [MoO2Me2(2,2′-bipyridine)] (5), [MoO2X2(4,4′-dimethyl-2,2′-bipyridine)] (X = Cl (2), Me (6)), [MoO2Me2(4,4′-di‑tert‑butyl‑2,2′-bipyridine)] (7) and [MoO2X2(4,4′-dinonyl-2,2′-bipyridine)] (X = Cl (4), Me (8)) have been prepared and examined as catalysts in extractive and catalytic oxidative desulfurization (ECODS) of a simulated diesel fuel (3000 ppm S) containing dibenzothiophene, 4-methyldibenzot...
Large-pore silica spheres as support for samarium-coordinated undecamolybdophos...
Mirante, Fátima; Alves, Ana C.; Julião, Diana; Almeida, Pedro L.; Gago, S.; Valença, Rita; Ribeiro, Jorge; De Castro, Baltazar; Granadeiro, CarlosA novel composite has been prepared through the immobilization of the Keggin sandwich-type [Sm (PMo11O39)(2)](11-) anion (SmPOM) on large-pore silica spheres previously functionalized with trimethylammonium groups (TMA). The resulting SmPOM@TMA-LPMS material has been evaluated as heterogeneous catalyst in a biphasic desulfurization 1:1 diesel/extraction solvent system using H2O2 as oxidant. Preliminary experime...
A sustainable peroxophosphomolybdate/H2O2 system for the oxidative removal of o...
Julião, Diana; Gomes, Ana C.; Cunha-Silva, Luís; Valença, Rita; Ribeiro, Jorge C.; Pillinger, Martyn; de Castro, Baltazar; Gonçalves, Isabel S.Highly efficient, deep desulfurization of a multi-component model diesel containing benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved by using the peroxophosphomolybdate [(n-C4H9)4N]3{PO4[MoO(O2)2]4} (Q3PMo4) directly as catalyst, and aqueous H2O2 as oxidant. Q3PMo4 behaves as a heterogeneous catalyst in the complete oxidation of the various sulfur compou...
Dichlorodioxomolybdenum(VI) complexes bearing oxygen-donor ligands as catalysts...
Julião, Diana; Gomes, Ana C.; Cunha-Silva, Luís; Pillinger, Martyn; Lopes, André D.; Valença, Rita; Ribeiro, Jorge C.; Gonçalves, Isabel S.The complexes [MoO2Cl2(DMB)2] (1) and [MoO2Cl2(DEO)] (2) (DMB = N,N-dimethylbenzamide, DEO = N,N′-diethyloxamide) have been evaluated as catalysts in extractive-catalytic oxidative desulfurization (ECOD) of a simulated diesel fuel. Using the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) as extraction solvent and H2O2 as oxidant, ultra-deep desulfurization (S-content from 3000 ppm to <...
Desulfurization of liquid fuels by extraction and sulfoxidation using H2O2 and ...
Julião, Diana; Gomes, Ana C.; Pillinger, Martyn; Valença, Rita; Ribeiro, Jorge C.; Gonçalves, Isabel S.; Balula, Salete S.Efficient and recyclable liquid–liquid extraction and catalytic oxidative desulfurization (ECODS) systems for the removal of refractory sulfur compounds from liquid fuels are reported that use the cyclopentadienyl molybdenum tricarbonyl complexes [CpMo(CO)3Me] (1), [CpMo(CO)3(CH2-pC6H4-CO2Me] (2) and [CpMo(CO)3CH2COOH] (3) as catalyst precursors. An ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate,...
Catalytic oxidative/extractive desulfurization of model and untreated diesel us...
Ribeiro, Susana O.; Julião, Diana; Cunha-Silva, Luís; Domingues, Valentina F.; Valença, Rita; Ribeiro, Jorge C.; Castro, Baltazar de; Balula, Salete S.The desulfurization efficiency of various hybrid zinc-substituted polyoxometalates ([PW11Zn(H2O)O39]5−, abbreviated as PW11Zn) was here investigated for the first time and optimized using sustainable systems conciliating successfully the liquid–liquid extraction and the oxidative catalytic process. Initially, the desulfurization studies were performed using a model diesel containing a mixture of the most refrac...
A recyclable ionic liquid-oxomolybdenum(VI) catalytic system for the oxidative ...
Julião, Diana; Gomes, Ana C.; Pillinger, Martyn; Valença, Rita; Ribeiro, Jorge C.; Gonçalves, Isabel S.; Balula, Salete S.The oxidative desulfurization of model and real diesel has been studied using the complex [MoO2Cl2(4,4′-di-tert-butyl-2,2′-bipyridine)] as (pre)catalyst, aq. H2O2 as oxidant, and an ionic liquid as extraction solvent. Under moderate conditions (50 °C) and short reaction times (<3 h), dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could be completely removed from the model diesel. Th...