High-temperature study of zirconia gels: Evolution of surface area and porosity on calcination in a vacuum

Abstract

Zirconium dioxide, prepared by dehydration of a zirconia gel, was calcined in a vacuum at temperatures ranging from 573 to 1173K, in order to investigate the evolution of specific surface area and porosity as a function of the calcination temperature. The results are compared with those previously obtained for samples heated in air. Samples fired up to 773 K were found to be basically microporous, with surface areas ranging from 142 to 93 m 2g −1. Calcination at 973 K led to total elimination of microporosity and reduction of surface area by about 50%. In the temperature range 773–1173 K, the most frequent pore radius was found to increase from 1.5 to 10.5 nm as the temperature was raised.