Summary Using temperature-programmed desorption (TPD), we have investigated the interaction of carbon dioxide with alkali-metal cation-exchanged faujasite type zeolites (LSX, X and Y). TPD in the temperature range between 300 and 500 K results in desorption profiles of different intensities depending on the kind of cation and the aluminium content of zeolites. For NaX the desorbed amount corresponds to about one percent of the saturation capacity at 298 K. In case of NaX and X type zeolites exchanged with Cs+ ions an additional desorption peak above 500 K could be observed. Taking into account desorption curves of different heating rates, desorption energy distribution functions were calculated by using an extended integral equation. Initial adsorbed CO2 could be assigned to carbonate species in different environments by DRIFT spectroscopy.
Authors:Yu. Goltsov, L. Matkovskaya, V. Il'in, and V. Golovaty
The results of investigation of the influence of encapsulation on the mechanism of thermal decomposition of cyanide transition
metal complexes, based on data obtained by methods of differential thermal analysis (inert atmosphere) and thermodesorption
(mass-spectral monitoring of gaseous products) are represented. It was established, that encapsulation of cyanide iron(II)
and cobalt(III) complexes in faujasite type zeolite results in the hydrolytic mechanism of thermal destruction of complexes,
unlike to bulk analogues, which is determined by essential decreasing of the temperature of complex anions encapsulated destruction
beginning, up to temperatures while zeolite water molecules are saved; the gaseous products of thermal destruction composition
is determined by the peculiarities of localization of cations of different nature in inclusion compounds.