The Measurement of Pore Size Distributions, Surface Areas, and Pore Volumes of Zirconia and Zirconiasilica Mixed Oxide Stationary Phases Using Size Exclusion Chromatography

Size exclusion chromatography was used to evaluate the surface areas, pore volumes, and pore size distributions of a variety of zirconias and silica-zirconia composites. In addition to the size exclusion results presented, the zirconias had been previously analysed using nitrogen sorption experiments making comparisons to established methods feasible. Agreement between the nitrogen sorption and size exclusion techniques was reasonably good with the size exclusion method serving to illustrate the chromatographic significance of the pore structure. Due to the stabilisation of the amorphous silica-zirconia composites the surface areas were shown to be much higher than the surface areas of the zirconias. However, after crystallisation the surface area decreased very rapidly. The results also illustrate that the inclusion of salts during calcination allows the widening of the pores for amorphous materials and increases the pore volume of both amorphous and crystalline materials.