Microstructure and quantitative estimation of the micropore-size distribution of an alumina-pillared clay from nitrogen adsorption at [formula omitted] and carbon dioxide adsorption at [formula omitted

Abstract

Several approaches have been considered and compared in order to characterize the microporous structure of an alumina intercalated clay from nitrogen and carbon dioxide adsorption. The Dubinin–Astakhov (DA) equation, the Horvath–Kawazoe (HK) and the Jaroniec–Gadkaree–Choma (JGC) methods as well as the density functional theory (DFT) have been applied to the adsorption data for both slit-like and cylindrical pore geometries. The effect of the temperature of the thermal treatment on the microstructure of the resulting pillared materials has been investigated by analyzing the micropore-size distributions (MPSDs) of samples calcined at temperatures between 473 and 873 K . The results from nitrogen adsorption at 77 K and carbon dioxide adsorption at 273 K have also been quantitatively compared to characterize these materials. It has been found that the ultramicropores generated by the pillaring process were the most deteriorated at the highest calcination temperatures whereas the mesopores were not significantly affected.