9172401570

particles of acidic or basie character, IR spectroscopy (also after pyridine adsorption) and NMR spectroscopy of solid State. One of the sections presents the results referring to the supported metallic phase. Chapter 6 presents the conclusions and the last chapter gives the list of references used. According to the results, the largest specific surface area have the samples with the lowest amount of a modifier in the silica matrix, i.e. samples SiSnż0,05 O2 and SiSn_ż0,l O2. The Lewis acid centres appear on the surface of the gel systems obtained only for SiSn_ż0,25 O2, as proved by IR spectroscopy with pyridine adsorption. Analysis of the properties of SiSn_żl,0 O2 has shown that this system is composed of two separate phases Si02 and Sn02. The properties of metallic (Pt) catalysts based on the binary gels obtained have revealed that starting from sample Pt/SiSn* 0,25, the alloy PtSn₄ is formed, which can significantly affect the catalytic performance of the systems studied.

The outeome of the dissertation presented can be of interest for those working on development of supported metal catalysts and immobilization of organie molecules on supports.

10