CENTRO DE INVESTIGACION Y DESARROLLO EN CIENCIAS APLICADAS "DR. JORGE J. RONCO"
Unidad Ejecutora - UE
Synthesis, characterization and catalytic evaluation of H3PW12O40included in acrylic acid/acrylamide polymer for the selectiveoxidation of sulfides
R. FRENZEL; G. SATHICQ; G. ROMANELLI; L. PIZZIO; D. MORALES; M. BLANCO
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
ELSEVIER SCIENCE BV
Lugar: Amsterdam; Año: 2016 p. 124 - 124
A series of hybrid materials (SAPTPA) based on tungstophosphoric acid H3PW12O40(TPA) included inacrylic acid/acrylamide polymer (SAP) were synthetized. The samples were characterized by FT-IR, XRD,31P MAS-NMR, DTA-TGA, and the acidic properties were determined by means of potentiometric titra-tion with n-butylamine. Materials with 10, 20, 30 and 40% (w/w) TPA content in the solid (SAPTPA10,SAPTPA20, SAPTPA30 and SAPTPA40, respectively) were prepared by impregnating the polymer withtungstophosphoric acid water solutions. According to FT-IR and31P MAS-NMR studies, the main speciespresent in the samples is the [PW12O40]3−anion, which was partially transformed into [P2W21O71]6−and[PW11O39]7−anions during the synthesis and drying steps.Taking into account XRD results, these species are highly dispersed in the polymer matrix or appearas noncrystalline phases. The DTA-TGA results show that SAPTPA materials did not undergo any remark-able chemical changes up to 200◦C. Additionally, the SAPTPA materials showed strong acid sites whosenumber increased as the TPA content in them was higher.The materials obtained by impregnation of TPA onto the polymer matrix present suitable physico-chemical properties to be used as catalysts in the selective oxidation of sulfides to the correspondingsulfoxide/sulfone using acetonitrile as solvent and H2O235% w/v as a clean oxidant.The SAPTPA40 catalyst was appropriate for the selective sulfide oxidation in heterogeneous conditionsand can be reused without significant loss of its catalytic activity. A convenient and selective procedurefor oxidizing sulfides to sulfoxides or sulfones by varying the H2O2/substrate ratio and the temperaturewas found.