الفهرس 
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Abstract
The present study represents a piece of work of an
experimental nature on theoritical banes. The results obtained from the present investigations are of indu-strial importance. They are to be applied in hydrogen-ation - dehydrogenation process used in nuclear tech-nology for heary water production using the chemical exchange between hydrogen and water on the surface of Nickel catalysts spread on metal oxide promoters.
The present work is an extension for a series of works and aims to add a new catalytic system to those produced,and improved before. The choice of the mixed oxide promoters suitable to ’support NiCkel is based on theoritical and experimental aspects. As afirst promoter for Nickel chromia was proved to be suitable. The -choice of the second promoter was more difficult. Several experimental trials were carried out on metal oxides to obtain the most suitable one. Because the melting point of the metal oxide promater plays an important role to produce mixed crystals,formed during the catalyst prep-aration, Zirconium oxide of high melting point has been
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chosen as a second promoter for nickel.
In the present study,to proceed hydrogenation-dey-
drogenation processes, several catalysts of different
compositions represnting ’such system were prepared
by the Co- precipitation technique.This techniqe
represents one of the main procedures applied in
technology. Metal Nitrates were proved to be the moat suitable starting materials to produce the selected
/ Zr02 system. The corresponding metal nitrates were. precipitated as carbonates, wns’zied, dr ied, sieved, calcined and produced at the proper expenimental condition. The obtained materials were found to be
pyropheric in nature, therefore it has been stabilized against spcultanous oxidation in atmosphere. For the different catalyst representing the selected Ni/Cr203/ ZsOi system, the specific surface area, the pore volume, x-ray analysis and surface charateristic were studied and related to their catalytic activity
simple test reaction was applied for liquid phase activity measurements which is the theithal decomposition
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of hydrogen peroxide. The liquid phase catalytic activity measurements permitted the search for the catalyats resisting water condensation on their surfaces and exih-ibiting high catalytic activity in both liquid and vapour phase, the so- called ”Resonance catalyst ”.
The performance of the reaction at different tempe-ratures allowed the study of both kinetic.-and thermodynamic parameters such as reaction rate constant, activation energy, enth 1py, free energy of activation and entropy
of activation.
Discussion of the experimental results on scientific bases was carried out and related to that given in the literature.