Aluminated zeolites β and their properties Part 1.—Alumination of zeolites β

Abstract

Zeolite β, a highly siliceous zeolite with a framework Si/Al ratio of about 19, has been aluminated with an aqueous solution of NaAlO ₂ . The process of alumination has been investigated on the basis of the characterization of aluminated samples by means of XRD, FTIR and benzene adsorption techniques. The results show that aluminium species are inserted into the framework of zeolite β through occupying the inherent structural vacancies and the vacancies generated during calcining synthesized zeolite β and through substituting framework silicon atoms, resulting in a decrease of the Si/Al ratio of the sample from 19 down to 3–4. Effects of the alkalinity of the solution, the amount of NaAlO ₂ used and the temperature on alumination were also investigated.