Abstract:
This work studies the nickel anchored on several oxides, in the aim to be used as
benzene hydrogenation catalyst. The metal ions, adsorbed on the oxide surface, are reduced
under ? radiation in aqueous solution. The radiolytic way has been proven to be powerful tool
for obtaining dispersed nanoparticules in colloidal state, deposited on a solid support or in
heterogeneous state. This process makes it possible to control the size of the particles, their
localization on the surface or into volume.
In the dispersed systems, the surface phenomena play an impotant role. The
adsorption of ions or molecules on the surface of the aggregates can modify their properties
and improve their activity. This is why we paid attention to the step of nickel adsorption on
the oxides by looking for the optimal condition in order to obtain an electrostatic interaction
between the metal ions and the surface of the support, favorable to a homogeneous and
durable nickel dispersion. This step was followed by UV- visible spectrophotometry and pH-
metry.
In the second step, the irradiated samples are characterized by various technics (MEB,
analyzes X and XRD). For the MgO support, Mg2Ni phases and Ni2Mg of nanometric size
were evidenced. These intermetallic compounds are of first importance in the energy field.
The nanoparticules of Ni/ZrO2 tested in catalysis in the benzene hydrogenation
reaction exhibit good catalytic properties. They are more active in decreasing temperature
than in increasing ones, indicating an anhencement of the catalytic activity during working.
