Ion exchanged Zeolite

Ion exchange zeolites are builders in washing powder, where they have gradually replaced phosphates to bind calcium. Calcium and, to a lesser extent, magnesium in water are exchanged for sodium in zeolite A. This is the largest application of zeolites today. Zeolites are essentially nontoxic, and pose no... 

Iwamoto, M., Mizuno, N. and Yahiro, H. (1991) Removal of nitrogen monoxide over copper ion-exchanged zeolite catalysts, Sekiyu Gakkaishi, 34, 375. 

Metal ion discharge, chemical identity of adsorbed intermediates, 38 19-20 Metal ion-exchanged zeolites, 31 13 Metallacycle mechanism, 41 323-324 Metallathiabenzenes formation of, 42 421 reaction with hydrogen gas, 42 420 Metallic catalysts, 27 3 see also specific catalysts... 

The NO reduction in the presence of an excess oxygen was performed by using the perovskite-alumina combined catalysts. Finally, a recent advance on NO reduction by using perovskites, supported metals and ion-exchanged zeolites was reviewed. 

Yokoyama, C. and Misono, M. Catalytic reduction of nitrogen oxides by propene in the presence of oxygen over cerium ion-exchanged zeolites II. Mechanistic study of roles of oxygen and doped metals. J. Catal, 1994, Volume 150,9-17. 

Alkali metal ion-exchanged zeolites and occluded alkali metal oxide zeolites have been investigated extensively and applied as basic catalysts for a variety of organic transformations (1,41,221,222). Zeolites modified with alkaline earth compounds have been applied much less frequently as base catalysts for organic reactions. 

Copper Ion-exchanged Zeolites as Active Catalysts for Direct Decomposition of Nitrogen Monoxide... 

K. The results indicate that Cu-ZSM5 is the most active catalyst at 773 K for the decomposition of dilute NO gas. The order of activity is Cu-ZSM5 > Ag-Co304 > La-Sr-Co(Cu)-0 > Pt/Al203 > Y-Ba-Cu-O/MgO. Regarding transition metal ion-exchanged zeolites, catalytic activities in the reduction of NO with or and the adsorption state of NO were extensively... 

The zeolitic host was ion-exchanged to introduce the desired transition metal cation. Synthesis of the salen ligands in the mesopores was conducted at room temperature under an inert atmosphere. To the ion-exchanged zeolitic material, the optically pure diamine in dichloromethane was added, in slight excess (1.2 equiv.) relative to the metal content. The appropriate amount of aldehyde was added to the slurry. The final material was Soxhlet-extracted with dichloromethane and toluene, respectively, until the solvent remained colorless. This procedure is described elsewhere in detail [51]. 

Synthetic inorganic ion exchangers Zeolites Synthetic zeolites (Figure 4.7) are available as powder, pellet, or bead. The greatest advantage of synthetic zeolites against natural zeolites is that they can be manufactured with a wide variety of physicochemical properties. The main disadvantages of synthetic zeolites are... 

Thomas et al. (53, 54) investigated the decomposition and subsequent reduction of aurichalcite and the ZnO-catalyzed solid-state conversion of ion-exchanged zeolite into cordierite. The decomposition of aurichalcite into mixed oxides of copper and zinc and the subsequent reduction of the... 

A further possibility for side-chain alkylation of toluene is oxidative methylation with methane. Catalysts with occluded alkali metal oxides, prepared by impregnating zeolites with alkali metal hydroxides followed by calcination, usually exhibit better performance.441 Further enhancement was achieved by impregnating ion-exchanged zeolites 442 Significant improvements in stability and the yields of Cg hydrocarbons were also observed when NaX was impregnated with 13% MgO which was found to increase the amounts of active sites.443... 

Efficient oxidation of alkanes with molecular oxygen can be attained using N-hydroxyphthalimide combined with Co(acac) (n = 2,3).1121 According to a new concept, photocatalyzed selective oxidation of small hydrocarbons at room temperature is carried out over alkali or alkaline-earth ion-exchanged zeolites.1122... 

Figure 2. Frequency of the D6-ring band vs. degree of exchange for ion-exchanged zeolites...

Figure S. IR spectra of CO adsorbed on ion-exchanged zeolites. Numbers are degree of exchange...

Transition metal ion-exchanged zeolites possess interesting properties. 

---