Nanocrystalline Mesoporous γ-Alumina Powders “UPMC1 Material” Gathers Thermal and Chemical Stability with High Surface Area

• DOI: 10.1021/cm061489j
• Publication Date: 2006-10-04T11:12:38Z
• Authors: Cédric Boissière; Lionel Nicole; Christelle Gervais; Florence Babonneau; Markus Antonietti; Heinz Amenitsch; Clément Sanchez; David Grosso
• Keywords: Nanocrystalline material; Thermal Stability; Tetragonal crystal system; Specific surface area; Metastability

The designed elaboration of alumina sub-micrometric spherical powder that combines 3D ordered mesoporosity high accessibility, nanocrystalline structure, and thermal stability up to 900 °C is reported. strategy used elaborate such new materials labeled "UPMC1" involves specific block-copolymer templating, aluminum sol−gel chemistry, tuned aerosol generation (spray drying), sequential treatments allow designing a whole set mesoporous catalytic supports by adjusting ceramization conditions between 700 °C. When calcination temperature reaches °C, the network remains amorphous displays structural features highly porous (i.e., porosity, 0.56 cm3·g-1; surface area, 403 m2·g-1; well-calibrated pore diameter, 13 nm). After 30 min at crystallization into γ-Al2O3 particles around 6 nm has occurred, which modified characteristics 0.34 134 12.5 nm) without destroying mesostructure. Both crystalline final present remarkable properties with unique amphoteric γ-alumina (40% tetragonal acid sites) have great potential application in catalysis, environment, as an adsorbent. work points out ability stabilize or metastable structure higher temperatures than what observed for nonordered analogous systems. Such phenomenon discussed on basis extensive characterization mainly based TEM, XRD, 29Al high-resolution solid-state NMR.