9172401569

Summary

The paper presents results of a study on potential supports of the following metallic catalysts SiC>2, Si02-Sn02 and Sn02- The catalytic Systems were obtained by the sol-gel method in anhydrous environment.

Supported metallic catalysts are used in a large number of industrial processes, important from the point of view of natural environment protection and generał industrial development. Among them of key importance are the catalysts of fuel cells, motor vehicle catalysts, those used for hydrogen generation and a wide rangę of catalysts used for petrochemical or Chemical processes.

The main challenge in designing a metallic catalyst is to achieve a proper exposure of the metal, its highest possible dispersion and activity and then to make it resistant to sintering and poisoning, i.e. to the process of catalyst deactivation. For the reactions taking place in high temperatures, for the catalytic processes those at above 500°C, the dominant mechanism of catalyst deactivation is sintering. As predicted by the Technology Vision 2020¹ programme, the understanding of mechanism of metal sintering on the support surface should stimulate development of the present and next generation of support materials. In the last decade the concept of stabilisation of smali metallic groups has again attracted the interest of research groups because of the new possibilities offered by the sol-gel technology in controlling the porous structure of the catalyst. This renewed interest has prompted the subject of this doctoral dissertation.

The doctoral dissertation is written in Polish, but includes the summary in Polish and in English. The summary is followed by introduction (chapter 1). The survey of literaturę in the field, divided into 6 sections, is presented in chapter 2. The papers discussed concern individual components of the catalytic systems and changes following from the presence of another component in the fundamental matrix. The sol-gel method is described, with water in the initial system and in anhydrous environment. The chapter ends with some generał information on metals on supports and methods of molecule immobilisation on silica gel. The aim of the study is presented in chapter 3, while chapter 4 is devoted to the experimental part of the study (methods of synthesis and product characterisation). The results are presented and discussed in chapter 5, divided into 8 sections covering the textural, X-ray and thermogravimetric analyses, SEM results, thermally programmed desorption of probe

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Technology Vision 2020 - The U.S. Chemical Industry - Strategie plan for Chemical industry aimed at development of competitiveness of U.S. economy. Its members are the American Chemical Society (ACS), American Chemistry Council (ACC), American Institute of Chemical Engineers (AIChE), Council for Chemical Research (CCR), Synthetic Organie Chemical Manufacturers Association (SOCMA).