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T. D. Khokhlova, E. V. Vlasenko, N. A. Zubareva, Van Nguyen, S. N. Lanin
Adsorption
of hydrocarbons from solutions and gas phase on silica and alumina, modified
with silver and gold ions
Abstract
Immobilization of cations Ag+ on the silica, alumina and anions AuCl4-
on aminosilica and alumina is carried out. By a method of inverse gas
chromatography it is shown the selectivity of Ag(I)-silica in separation of
alkanes, alkenes, alkynes and aromatics. Dependence of the Ag(I) and
Au(III)-composites capacity on phenylacetylene (PHA) by the carrier nature, the
specific surface area and the method of immobilization of the metal ions is
considered. The adsorption isotherms of PHA in octane solutions are measured.
It is found that PHA capacity of the composites prepared by immobilization of
ammoniate of silver nitrate on silica in several times more than on alumina
with the same silver content and than the composites prepared by immobilization
of silver nitrate on silica. The Au(III)-alumina capacity on PHA was
significantly higher than the Au(III)-aminosilica. The greatest capacity on PHA
respectively 0.83 and 0.88 molecule on metal ion is observed for the
Ag(I)-silica and Au(III)-alumina. In spectra of diffuse reflectance in visible
region of the Au(III)-aminosilicas there is a significant shift of the
absorption band maximum at reduction of the content of immobilized anions
AuCl4-. That indicates formation of coordinate bonds between the free
aminopropyl groups of the aminosilica carrier and the atom of gold. Formation
of such bonds is hindered the adsorption of the PHA on Au(III)- aminosilica
with low content of gold.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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