Formation of Micro/Macroporous Hierarchical Spheres of Titanosilicate Umbite

Abstract

Polycrystalline spheres of up to 2 mm diameter of microporous titanosilicate K 2 TiSi 3 O 9 ·H 2 O with umbite structure (Ti-umbite) were prepared without the use of organic structuring agents. The spheres, while preserving the inherent microporosity of the umbite type-material, are organized as hierarchical materials with macropores in the 0.1-1.4-µm size range. Ti-umbite spheres were only produced by hydrothermal synthesis under rotation conditions, at 230°C by using a solution with the following molar composition: 0.284 K 2 O/0.287 Na 2 O/SiO 2 /0.095 TiO 2 (anatase)/30.8 H 2 O, and

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