Salt occlusion

At 26 C (P/Po = 0.4) the equilibrium loading for n-butane Is 1.17 mmoles/g. This loading does not differ greatly from the lsobutane equilibrium capacity (1.01 mmoles/g) suggesting that these Rb-offretlte crystals are probably free from salt occlusion and/or stacking faults. 

I. Hussain, I. Gameson, P.A. Anderson, M. Slaski, P.P. Edwards, and A. Dyer, A Route to the Dispersion of Ultrafine Cobalt Particles on Zeolite Na-X through Salt Occlusion and Reduction, j. Chem. Soc., Dalton Trans., 1996, 775-781. 

Solid-state ion exchange may be carried out in stoichiometric mixtures of salts (or oxides) and zeolites, related to the Al content (in case of aluminosilicates) of the framework. However, it also works with under-stoichiometric mixtures or mixtures containing an excess of the in going cation. In the latter case, the excess may be removed by brief extraction of the solid-state reaction product with water also, salt occlusion may occur during heat treatment [2-3]. Thus, with many important salt(oxide)-zeolite... 

J.A. Rabo, Salt Occlusion in Zeolite Crystals , in J.A. Rabo (Editor), Zeolite Chemistry and Catalysis , ACS Monograph 171, Am. Chem. Soc., Washington,... 

The studies on ion exchange in zeolites almost exclusively concerned the conventional ion exchange. Briefly, this is carried out by suspending crystallites of a zeolite with cation A in a salt solution of the cation B which is supposed to go into the zeolite structure and there replace cation A. However, there were some early observations that ion exchange with zeolites might occur in solid-state as well [10-14]. Thus, Rabo et al. [10-12] described, in their work on salt occlusion in zeolites, the replacement of protons by sodium cations. They calcined a mixture of NaCl and Na-Y which contained residual acidic OH groups. 

Figure 13. H2S-to-COS conversion on sodalites with salt occlusion.

Pendant donor groups can occupy otiierwise vacant coordination sites, thus precluding oligomerization/ polymerization, salt occlusion, and coordination of solvent... 

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