Textural and fractal properties of CuO/Al 2 O 3 catalyst supports

Abstract

Reactive amorphous aluminas with a high surface area, suitable as a precursor for catalyst supports, are obtained by flash calcination of gibbsite in a reactor for pneumatic transport in the dilute two phase flow regime. In the present paper we study the effects of the gibbsite dehydration temperature on the textural and fractal properties of activated aluminas. The parameters of the pore structure for all samples were evaluated from nitrogen adsorption-desorption isotherms. On the basis of the sorption-structure analysis, the fractal dimension of the aluminas surface were determined by three methods, according to Pfeifer and Avnir, Neimark et al. and Mahnke and Mögel, with a goal to compare obtained values. As expected, a good agreement between the results of these methods was achieve. The values of the fractal dimension of activated aluminas increase with the increase of the temperature of thermal treatment, indicating that the irregularities of their surfaces are greater.