CONICET | Buscador de Institutos y Recursos Humanos

The gas-phase conversion of 1,3-diols was studied on catalysts containing different active sites and using1,3-butanediol as a model molecule. Transformation of the diol primary and/or secondary OH groups bydehydration and dehydrogenation reactions yields valuable oxygenates combining OH and C C, OH andC O or C C and C O functions, along with other compounds. A series of single oxides with differentacid?base properties, copper?silica and copper-single oxide catalysts were prepared by several methodsand characterized by TPR, XRD and N2O chemisorption.Acid?base oxides transform 1,3-butanediol at low rates. Oxide electronegativity determines the mainreaction pathway: acidic oxides promote 1,3-butanediol dehydration toward unsaturated alcohols andolefins, whereas basic oxides dehydrogenate-dehydrate the diol toward the unsaturated ketone.The effect of Cu0in monofunctional copper?silica, or bifunctional copper/acid or copper/base catalysts,is to increase the reaction rate and to shift the reaction pathway toward 1,3-butanediol dehydro-genation. The metal dispersion depends on the preparation method by impregnation, ion exchange orco-precipitation. Small Cu0particles strongly adsorb reactant and products allowing consecutive reac-tions to take place after initial dehydrogenation. In bifunctional catalysts, the role of the acid or base sitesis to promote consecutive dehydration-hydrogenation or C C bond cleavage reactions, respectively.