Effect of irradiation with gamma-rays on the surface and catalytic properties of SiO2-Al2O3 and Li2O-impregnated SiO2-Al2O3 systems

Abstract

Coprecipitated SiO₂-Al₂O₃ (Al₂O₃=33.2 mol%) and Li₂O-impregnated SiO₂-Al₂O₃ containing 1, 2.5 and 5 mol% Li₂O were prepared. The textural properties were determined by following the adsorption of nitrogen at 77K. The surface acidities were determined from pyridine adsorption at 423 K. The catalytic conversion of isopropanol on the catalyst prepared was carried out using the pulse microcatalytic technique.

The surface area decreased and the pore size increased upon irradiation with γ-rays (dose⩾ 30 M rad). The acidity decreased upon impregnation with Li₂O and/or irradiation with γ-rays.