Valeria Palermo

Role of vanadium and pyridine in heteropolycompounds for selective oxidation of alcohols with hydrogen peroxide

AbstractThis study describes the application of heteropolyacids H3PMo12O40, H4SiMo12O40, H4PMo11VO40, H5PMo10V2O40, H9PMo6V6O40, and a hybrid pyridine-modified heteropolyacid with Keggin structure for selective oxidation of alcohols to ketones or aldehydes using aqueous hydrogen peroxide and acetonitrile as solvent. Performance of these different catalysts in 1-phenylethanol oxidation was studied. Influence of reaction temperature, amount of catalyst and hydrogen peroxide and reaction time on the yield of acetophenone was investigated to obtain optimal reaction conditions. Oxidation ability of the catalyst depended on the number of vanadium atoms present in the Keggin ion and to a lesser extent on pyridine substitution in the Keggin secondary structure. In order to explore the applicability of the method for selective oxidation of alcohols to ketones or aldehydes, various alcohols were investigated according to the general procedure using hybrid pyridine-modified heteropolyacid. Graphical AbstractThis study describes the application of heteropolyacids H3PMo12O40, H4SiMo12O40, H4PMo11VO40, H5PMo10V2O40, H9PMo6V6O40, and a hybrid pyridine-modified heteropolyacid with Keggin structure for selective oxidation of alcohols to ketones or aldehydes using aqueous hydrogen peroxide and acetonitrile as solvents.

Simple and Friendly Sulfones Synthesis Using Aqueous Hydrogen Peroxide with a Reusable Keggin Molybdenum Heteropolyacid, Immobilized on Aminopropyl-Functionalized Silica

Keggin molybdenum heteropolyacid (H3PMo12O40), immobilized on aminopropyl-functionalized silica catalysts, were made using two immobilization methods: incipient wetness and equilibrium adsorption. The material prepared for the equilibrium adsorption technique was found to be a highly efficient, ecofriendly, and recyclable heterogeneous catalyst for the selective oxidation of sulfides to sulfones in excellent yields, under mild reaction condition using 35% w/v aqueous hydrogen peroxide as the oxidant.

Selective Oxidation of Sulfides to Sulfoxides Using Modified Keggin Heteropolyacids as Catalyst

GRAPHICAL ABSTRACT Abstract The use of modified Keggin phosphomolybdic heteropolyacids (HPA) (V and Al) as catalysts in the selective oxidation of sulfides to the corresponding sulfoxides is reported. Excellent yields were obtained (13 examples: 79%–95%), using 35% (w/v) aqueous hydrogen peroxide as oxidant, and acetonitrile as solvent at 25°C. The relationship between the electron densities of the sulfur atoms, which was estimated by molecular theoretical calculations, and the oxidative relativities of the sulfur-containing compounds was also investigated. The results indicate that the time for 100% conversion decreases with an increase in electron density.

Synthesis of CuO powders using different fuels for selective surfaces

María Celeste Gardey Merino1, José Antonio Alonso2, Patricia Vázquez3, Valeria Palermo3, Silvina Lassa4, Mariana Rodriguez1, Ariel Bordón1 1Grupo CLIOPE-UTN Regional Mendoza, Ciudad De Mendoza, Argentina, 2Instituto de Ciencia de Materiales de Madrid (CSIC), Madrid, Spain, 3CINDECA, CCT CONICET La Plata,, La Plata, Argentina, 4MEByM IANIGLA CONICET-Mendoza,, Mendoza, Argentina E-mail: mcgardey@frm.utn.edu.ar