L’effet de pH et de la température de calcination sur la microporosité d’une argile locale

Abstract

Effects of the degree of hydrolysis of the Al (expressed as the pH or OH/Al of the pillaring solution) and the calcination temperature on the ultimate microporisity of the Al-pillared clays are studied. The results showed that clays prepared from an olimeric solution with an OH/Al-2 yielded the largest particle size (159.66 nm) and the lowest overall surface area (193.32 m 2 g –1 ). Micropore size of clays calcined at 350°C (1.22 nm) were consistently lower than those same clays calcined at 550°C (~1.35 nm). The overall surface area followed the same trend. This is due to a collapse/sintering of the Al2O3 pillars with calcination at the higher temperature, which reduces the interlayer spacing as confirmed by XRD.