Zeolites silver-loaded

It has been reported (Calzaferri et al., 1984) that oxygen from water is evolved upon irradiation of a silver-loaded zeolite (a group of alumino-silicates) suspension according to the following overall stoichiometry ... 

CHARACTERIZATION AND ETHYLENE ADSORPTION PROPERTIES OF SILVER-LOADED FER ZEOLITE POTENTIALLY USED AS TRAP MATERIAL OF COLD-START HYDROCARBON EMISSION FROM VEHICLES... 

The adsorption properties of silver- and cupper-loaded zeolites for C2 and C3 hydrocarbons were investigated to explore excellent materials for cold-start hydrocarbon trap. The adsorption property and the stability of the adsorbents depended significantly on the metal species and host zeolites. It has turned out that silver-loaded ferrierite zeolite is the promising material with excellent olefin selectivity, high adsorption capacity, desirable storage ability and hydrothermal stability. 

For permanent fixation of 1 adsorption on silver-loaded adsorbents, such as zeolites, silica, or alumina, will be the choice [PI, W2]. The process is simple, the bed temperature may be relatively high, the product is a dry solid, the chemisorbed iodine is highly insoluble, and the adsorbent is very efficient in removing both organic and inorganic iodine from gas streams. 

AgNaZSM-5 catalysts were investigated for the selectively catalytic reduction of NO by methane in the excess of oxygen. It was clearly depicted that the conversion rate of NO to N2 had a linear dependence on the silver loading (4.32 13.64%), which indicated that all silver species in the zeolite were active for the CH4-SCR reaction. The presence of excessive oxygen in the feed gas favored the CH4-SCR reaction. The temperature programmed desorption profiles in He and 2%CH4/He after the co-adsorption of NO and O2 revealed that surface nitrates were formed on silver catalyst, and could be effectively reduced by methane... 

Fig. 16.2 A, Correlations of silver loading with the amount of silver in the zeolite channels (a) and deposited on the zeolite surface (b). B, Variation of NO conversion to N2 on increasing Ag loading on the H-ZSM-5 zeolite, from Ref. [23].

Silver(I)-loaded zeolites and silica-alumina can be used in carbohydrate coupling. The Ag(I) activates the 1-Br-substituent in this nucleophilic substitution. Because of the size of the reactants only the outer surface of the zeolites is active. 

AgX) Silver nitrate impregnated silica Purex Silver reactors Charcoal Organic sorbers AgXI Agl Agl, AgI03 Iodine loaded charcoal, I2 Iodine loaded material, I2 zeolite ... 

Based on this screening and consideration of the products of the iodine capture technologies, Agl, Cul, Pblo, Ba(I0o)2> Ca(I03)2 Pb(I03)2 Hg(I0o)2, iodine-loaded silver moraenite (AgZI) and iodine-loaded lead zeolite X (PbXI) were selected for incorporation into cement and subsequent leach testing. 

Hydrocarbon sorbate vibrations. IINS spectra have been recorded for a number of simple sorbate molecules within aluminosilicate zeolites, including hydrogen in A (40, 41). acetylene in X (4, ethylene in A (42) and X (44-46). and p-xylene (42) in X type materials. In addition to intramolecular modes, where interaction between the sorbate and the non-framework cations is strong (for example in the ethylene - silver zeolite A system (42)), vibrational transitions associated with sorbate motion with respect to the zeolite s internal surface can be observed. The latter modes, and the dependence of their frequencies on loading, structure and composition are of particular interest as they convey detailed information about the character of the zeolite - sorbate... 

The other interesting group of radiation-induced silver nanoclusters looking for possible catalytic applications are those based on zeolites. In this case, Ag+ cations are loaded into zeolites by cation exchange with an AgN03 solution at room tanperature. The product is dried, the metal ions oxidize and are then irradiated by gamma rays at 77 K (Sadlo et al. 2006). 

---