The aim of the present work was to combine different physicochemical techniques, namely X ray diffraction, IR spectroscopy,
and multinuclear (29Si and 27Al) solid-state NMR spectroscopy, to study the aluminum distribution and to determine the silicon–aluminum ordering in the
Y-zeolite framework when the latter was submitted to acid leaching (HCl, HNO3, H2SiF6). It was shown that all acids were effective in removing Al from the framework. Moreover, the extra-framework Al extraction
from the lattice was dependent on the nature and the concentration of the acid. After the dealumination treatment, different
species (silanol nest, six-coordinated non-framework Al) were detected. The investigation showed that the breakdown of the
parent Y-zeolite mainly depends on the degree of dealumination.