Thermally Stable Nanocrystalline Mesoporous Gallium Oxide Phases

Abstract

AbstractSemicrystalline and fully crystalline mesoporous galliumoxide phases were synthesized in the presence of ionic and non‐ionic structure directing agents via Evaporation‐Induced Self‐Assembly (EISA) and Self‐Assembly Hydrothermal‐Assisted (SAHA) methods respectively. EISA led to partially crystalline mesoporous gallium oxide phases displaying unimodal pore size distribution in the range of ca. 2–5 nm and surface areas as high as 300 m2/g. SAHA led to nanocrystalline mesoporous uniform micron‐sized gallium oxide spheres (ca. 0.3–6.5 μm) with narrow size distribution displaying cubic spinel type structure. These mesophases displayed surface areas as high as ca. 221 m2/g and unimodal pore size distribution in the 5–15 nm range. Textural properties such as surface areas and pore sizes were effectively fine‐tuned by the nature and relative concentration of the structure directing agents. Due to their high surface areas, tunability of pore sizes and the nature of the wall structure, these gallium oxide mesophases could find potential applications as heterogeneous catalysts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)