This paper reports sol-gel synthesis and properties of several major ceramic adsorbents. Nanostructured y-alumina, zirconia and titania adsorbents with uniform pore size distribution and an average pore diameter of about 3 nm are prepared by hydrolysis and condensation of corresponding metalorganic precursors. The as-synthesized adsorbents are in their meta-stable phases, and transform to their stable phases upon heat-treatment. The phase transformation accompanies a decrease in surface area and increase in pore size. Microporous (< 2 nm) silica adsorbents are prepared by the sol-gel method following a polymeric sol route. Doping alumina in silica adsorbents improves their thermal and hydrothermal stability. A sol-gel granulation process based on the oil-drop principle is described for preparation of y-alumina granular particles. A solutionsol mixing coating method is used to coat active species on the pore surface of the granular y-alumina particles. The sol-gel derived granular adsorbents exhibit high crush strength, good attrition resistance and desired pore structure. Experimental results show that the sol-gel derived CuO/y-alumina and CuCl/y-alumina granular adsorbents have better properties for sorption of S02 and ethylene than similar adsorbents prepared by the conventional methods.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry