Change in catalytic activity of silica-alumina catalysts during sintering.

Abstract

The deactivation function of silica-alumina catalysts during steam sintering is presented. Silica-alumina catalysts sinter rapidly at high temperature in steam atmosphere, undergoing irreversible changes in both pore structure and acidic properties that result in deactivation. Change in acid strength distribution during sintering was well represented by a population balance equation. By combining this equation with the previous two models developed by the authors, one for the rate of decrease in surface area during sintering, the other for the relationship between catalytic activity and acidic properties, the deactivation function of the catalyst during sintering was found to be expressible in terms of its surface area. Changesin acidic properties and catalytic activity were well predicted by the model equations.