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Zirconia-pillared tetrasilicic fluoromicas are prepared from sodium tetrasilicic mica, Na-[Mg[sub 2.5]Si[sub 4]O[sub 10]F[sub 2]], using a commercial zirconyl acetate solution as the source of the zirconium polyoxocation pillars. Reproducible results are conveniently obtained without any preliminary heating of the pillaring solution, and the pillaring reaction is performed at ambient temperature. The resulting zirconia-pillared mica has a consistently higher crystallinity and layer spacing than pillared clays prepared from zirconyl chloride solutions adn shows significantly higher thermal stability, an important factor in potential catalytic applications. Zirconia-pillared tetrasilicic fluoromica is a microporous material containing two-dimensional galleries with a height of 11 [angstrom]. The surface area is high, about 300 m[sup 2]/g. After treatment in steam at 760[degrees]C for 17 h, the surface area is reduced only to [approximately]200 m[sup 2]/g. Thus, very small particles of ZrO[sub 2] dispersed between 10-[angstrom]-thick mica layers have been stabilized. 39 refs., 7 figs., 3 tabs. |
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