Vanadium oxides supported on hydrotalcite-type precursors: the effect of acid-base properties on the oxidation of isopropanol

Autor(es)

D. M. Meira ^[1] ; G. G. Cortez ^[2] ; W. R. Monteiro ^[3] ; J. A. J. Rodrigues ^[4]

Afiliação do(s) autor(es)

^[1] Faculdade de Engenharia Química de Lorena. Departamento de Engenharia Química. Laboratório de Catálise II - Brasil

^[2] Faculdade de Engenharia Química de Lorena. Departamento de Engenharia Química. Laboratório de Catálise II - Brasil

^[3] Instituto Nacional de Pesquisas Espaciais. Laboratório Associado de Combustão e Propulsão - Brasil

^[4] Instituto Nacional de Pesquisas Espaciais. Laboratório Associado de Combustão e Propulsão - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Chemical Engineering; v. 23, n. 3, p. 351-358, 2006-09-00.

Resumo

Vanadium oxide supported on hydrotalcite-type precursors was studied in the oxidation of isopropanol. Hydrotalcites with different y = Mg/Al ratios were synthesized by the method of coprecipitation nitrates of Mg and Al cations with K2CO3 as precipitant. The decomposition of these hydrotalcite precursors at 450°C yielded homogeneous MgyAlOx mixed oxides that contain the Al+3 cations totally incorporated into the MgO framework. The materials were characterized by chemical analysis, BET superficial area, X-ray diffraction, temperature-programmed reduction (TPR) and the reaction of isopropanol, a probe molecule used to evaluate the acid-base properties. The results of TPR showed that the reducibility of V+5 decreased with the increase in magnesium loading in catalysts. The X-ray diffraction patterns of Al-rich hydrotalcite precursors showed the presence of crystalline phases of brucite and gibbsite. It was shown that chemical composition, texture, acid-base properties of the active sites and also Mg/Al ratio strongly affect the formation of the products in the oxidation of isopropanol. The Al-rich catalysts were much more active than the Mg-rich ones, converting isopropanol mainly to propylene. (AU)

• Processo FAPESP: 04/02099-5 - Preparação, caracterização e estudo das propriedades superficiais de catalisadores V2O5/MgyAlOx na reação de decomposição de isopropanol
• Beneficiário: Débora Motta Meira
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico