Adsorption of hidrogen peroxide on the surface of silica - titania mixed oxide obtained by the sol-gel processing method

• Autor(a) principal: Gonçalves,J. E.
• Data de Publicação: 2007
• Outros Autores: Filho,U.P. R., Franco,D.W., Gushikem,Y.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Eclética Química
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-46702007000200007
• topic: sol-gel; silica-titania; hydrogen peroxide adsorption; porous material

This work describes the sol-gel mixed oxide SiO2/TiO2 property, ST, as prepared, and submitted to heat treatment a 773 K, STC. SEM and EDS images show, within magnification used, a uniform distribution of the TiO2 particles in SiO2/TiO2 matrix. Both, ST and STC adsorb hydrogen peroxide on the surface and through EPR and UV-Vis diffuse reflectance spectra, it was possible to conclude that the species on the surface is the peroxide molecule attached to the Lewis acid site of titanium particle surface, alphaTi(H2O2)+. As the material is very porous, presumably the hydrogen peroxide molecule is confined in the matrix pores on the surface, a reason why the adsorbed species presents an exceptional long lived stability.