Authors:Hanene Najar, Mongia Zina, and Abdelhamid Ghorbel
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.
Authors:Mohamed Triki, Hafedh Kochkar, Gilles Berhault, and Abdelhamid Ghorbel
Ruthenium catalysts have been prepared by incipient wetness impregnation of ruthenium(III) nitrosylnitrate, Ru(NO)(NO3)3 onto high surface area titanate supports obtained by hydrothermal treatment of TiO2 P25 in concentrated alkaline solutions. These Ru-containing catalysts were evaluated in the catalytic wet air oxidation of
p-hydroxybenzoic acid (p-HBZ), a model compound representative of phenolic pollutants present in olive mills wastewaters, at 413 K and 50 bars of
air. Two different titanates morphologies were tested as supports for this reaction: hydrogenotitanate nanotubes (HNT) obtained
with concentrated NaOH and hydrogenotitanate nanowires (HNW) formed in the presence of highly concentrated KOH solution. The
HNT and HNW supports and their corresponding supported Ru catalysts were characterized by means of N2 adsorption–desorption, XRD, UV and TEM analyses. Results showed that the use of high surface area titanate supports led to
catalysts much more active than similar Ru catalysts supported on conventional TiO2 supports.