Encyclopedia

  • Thermal and hydrothermal stability of pure and silica-doped mesoporous ALUMINA (cas 1333-84-2)s
  • Add time:09/03/2019         Source:sciencedirect.com

    Thermal and hydrothermal stabilities of solvent deficient derived pure alumina (PA) as well as silica-doped aluminas (SDA) with three different dopant concentrations (5, 15, 27% by weight) have been investigated for changes in phase and pore structure after calcination at high temperatures under air and steam/air atmospheres. For all aluminas, heat treatment results in decreased surface area and increased pore diameter. Starting at 700 °C, metastable to stable phase transformation occurs, causing a substantial change in the pore structure of all aluminas. By 1100 (PA), 1200 (15 SDA) and 1200 °C (27 SDA), the transition to α-Al2O3 was complete, respectively. No α-Al2O3 is observed for 5 wt % silica doped alumina (5SDA) under thermal calcination. Calcination in steam and air, instead of in air only, results in enlarged pore size and depressed temperature of alpha phase transformation for all aluminas. Results show that the silica dopant modifies the pores of the alumina, stabilizes the oxygen lattice of γ-Al2O3, and retards α-Al2O3 formation. This study of the thermal and hydrothermal stability not only suggests the applicability of 5SDA for catalytic reactions occurring at high temperature in the presence of steam, but also contributes to a better understanding of the structural features responsible for the improved thermal stability of these aluminas.

    We also recommend Trading Suppliers and Manufacturers of ALUMINA (cas 1333-84-2). Pls Click Website Link as below: cas 1333-84-2 suppliers


    Prev:Analysis of crystal phases of Na+-β/β"-ALUMINA (cas 1333-84-2)/YSZ composite prepared by vapor-phase synthesis from YSZ-toughened α-ALUMINA (cas 1333-84-2)
    Next: Original ArticleCreep study on ALUMINA (cas 1333-84-2) and ALUMINA (cas 1333-84-2)/SWCNT nanocomposites)

About|Contact|Cas|Product Name|Molecular|Country|Encyclopedia

Message|New Cas|MSDS|Service|Advertisement|CAS DataBase|Article Data|Manufacturers | Chemical Catalog

©2008 LookChem.com,License: ICP

NO.:Zhejiang16009103

complaints:service@lookchem.com Desktop View