STUDY OF THE INFLUENCE OF ALUMINA-CONTENT ON THE PORE STRUCTURE OF SYNTHETIC SILICA-ALUMINA CATALYSTS

Silica-alumina catalysts with Al2O3 contents ranging from 0 to 100 wt. % have been prepared by stepwise precipitation method, dried at 110 degrees C and subjected to heat treatment at 400 degrees C in vacuum. The adsorption and desorption of nitrogen have been studied on these catalysts at 77 K. The changes in the pore structures and the physical properties of the catalysts are analysed as a function of Al2O3 content. The catalysts have exhibited type A N-2-adsorption-desorption hysteresis loops below 12% Al2O3 content and type E hysteresis loops above this Al2O3 content.