2 documents found, page 1 of 1
New method for the immobilization of nitroxyl radical on mesoporous silica
Castanheiro, JE; Machado, A; Casimiro, M; Ferreira, L; Ramos, A; Vital, J; Fonseca, IThis work reports the covalent attachment of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (4- hydroxy-TEMPO) on the mesoporous silicas MCM-41 and SBA-15, by using ,4-diisocyanatobutane as a binder. The catalysts were characterized by nitrogen adsorption/desorption, XRD, TEM, TGA, DSC and FTIR spectroscopy. Catalytic tests were performed on the liquid phase oxidation of benzyl alcohol and the secondary alcohol ...
Esterification of fatty acids to biodiesel over polymers with sulfonic acid groups
Caetano, CS; Guerreiro, L; Fonseca, I; Ramos, A; Vital, J; Castanheiro, JEThe esterification of palmitic acid with methanol was studied using poly(vinyl alcohol) cross-linked with sulfosuccinic acid (SSA) and polystyrene cross-linked with divinylbenzene with sulfonic acid groups, as catalysts, at 60 ºC. It was observed that the PVAmatrixes with sulfonic acid groups were more active than the polystyrene ones. With the most active polymeric matrix (PVA_SSA40), an almost 90% equilibrium...