Tl-Exchange in Zorite and ETS-4

Abstract

Within recent years, titanosilicates and other octahedral-tetrahedral framework materials have attracted considerable attention due to their applications in catalysis, gas separation, energy storage, optoelectronics, radioactive waste management, etc. (Behrens et al. 1998; Lamberti 1999; Rocha and Anderson 2000; Zecchina et al. 2001). Before being synthesized under laboratory conditions, many of these materials were known as minerals. Engelhard titanosilicate ETS-4, which is now used in gas industry on a multitonn scale (Kuznicki et al. 2001), is a synthetic analogue of zorite, a framework sodium titanosilicate described in 1970s from alkaline complexes of the Kola peninsula, Russia (Mer'kov et al. 1973; Sandomirskii and Belov 1979). This and many other examples show that investigations of minerals are not only of mineralogical interest but may also provide important ideas for synthesis of new materials with important industrial applications.