Variables Influencing Final Properties of Catalysts

Abstract Variables influencing the preparation methods and the final properties of the catalysts. 

Keywords Metals, oxides Preparation Properties Supports Variables 

Variables influencing the preparation by precipitation, coprecipitation, precipitation-deposition, and impregnation can transform the chemical and physical properties, approaching to the equilibrium conditions. The main variables are as follows [1-11]  

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ANALYSES OF VARIABLES INFLUENCING FINAL PROPERTIES OF CATALYSTS... 

Experimental Materials. All the data to be presented for these illustrations was obtained from a series of polyurethane foam samples. It is not relevant for this presentation to go into too much detail regarding the exact nature of the samples. It is merely sufficient to state they were from six different formulations, prepared and physically tested for us at an industrial laboratory. After which, our laboratory compiled extensive morphological datu on these materials. The major variable in the composition of this series of foam saaqples is the aaK>unt of water added to the stoichiometric mixture. The reaction of the isocyanate with water is critical in determining the final physical properties of the bulk sample) properties that correlate with the characteristic cellular morphology. The concentration of the tin catalyst was an additional variable in the formulation, the effect of which was to influence the polymerization reaction rate. Representative data from portions of this study will illustrate our experiences of incorporating a computer with the operation of the optical microscope. 

Many properties and conditions influence the capability of materials to serve as catalysts for a particular reaction. First, the composition of the material is important, identified by the chemical elements or compounds present, and by their respective mass or molar fractions in the material. Furthermore, the structure and texture of the material, which are determined mainly by the preparation method employed, play an important role. The composition and structure of the bulk and the surface are interconnected with further properties of the material, such as acidity, basicity, redox potential, and electronic conductivity these properties are usually denoted as descriptors (cf. Klanner, 2004 Klanner et al, 2004 Farrusseng et al, 2005). Finally, the catalytic performance of a material does not depend solely on the material itself, but also on the conditions to which that material is exposed in the reaction, at a particular temperature, partial pressures of the reactants, total pressure, and space velocity of the feed. The descriptors of the material and the reaction conditions together are called input variables in the sequel. 

In this report we will show how some variables of catalyst preparation can influence the final mechanical properties, starting in some cases from tests on different commercial catalysts. 

Mat r variables of the catalyst preparation procedure can influence the mechanical properties of the final catalyst. It is remarked that this R-D step must be performed during the scale-up of catalyst production at the pilot scale. It is shown that the mechanical strength of the following catalysts can be improved in the following ways ... 

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