Papers by Keyword: Silver Clusters

Abstract: Two series of Ag-loaded β-zeolites with silica/alumina ratio of 25 and 36 were prepared by ion exchange technique. The silver loading was varied in a range of 2-10 wt%. The samples were characterized by low-temperature nitrogen adsorption, Infrared and UV-vis spectroscopy, and transmission electron microscopy. Adsorption/desorption properties of zeolites were examined using a specially designed setup. Toluene was used as a model hydrocarbon. It was found that adsorption capacity of zeolites grows up along with silver content increase till 8%, and reduces then. According to data of physicochemical methods, at low loading the silver exists in cluster and ionic forms, while at high loading agglomerated particles predominate, which worsens the adsorption properties.

Abstract: Silver sodalite crystals with hydroxyl guest anion and silver loading higher than 7.9 per unit cell were investigated. EPR spectra of sodalite, recorded just afer g-irradiation at 77K, shows a 9-line, near isotropic signal with giso=1.987 and hyperfine splitting of 8.3 mT. The signal decays completely above 200K. We assign the multiplet to silver octamer Ag8 n+ cluster and tentatively postulate that the cluster charge is +7.