Deutsch
 
Hilfe Datenschutzhinweis Impressum
  DetailsucheBrowse

Datensatz

DATENSATZ AKTIONENEXPORT

Freigegeben

Zeitschriftenartikel

Chemical and physical changes related to the deactivation of alumina used in catalytic epoxidation with hydrogen peroxide

MPG-Autoren
/persons/resource/persons58928

Rinaldi,  Roberto
Research Group Rinaldi, Max-Planck-Institut für Kohlenforschung, Max Planck Society;
Instituto de Química, Universidade Estadual de Campinas, PO Box 6154, 13083-970 Campinas, SP, Brazil;

Externe Ressourcen
Es sind keine externen Ressourcen hinterlegt
Volltexte (beschränkter Zugriff)
Für Ihren IP-Bereich sind aktuell keine Volltexte freigegeben.
Volltexte (frei zugänglich)
Es sind keine frei zugänglichen Volltexte in PuRe verfügbar
Ergänzendes Material (frei zugänglich)
Es sind keine frei zugänglichen Ergänzenden Materialien verfügbar
Zitation

Rinaldi, R., Fujiwara, F. Y., & Schuchhardt, U. (2007). Chemical and physical changes related to the deactivation of alumina used in catalytic epoxidation with hydrogen peroxide. Journal of Catalysis, 245(2), 456-465. doi:10.1016/j.jcat.2006.11.011.


Zitierlink: https://hdl.handle.net/11858/00-001M-0000-0024-21AC-C
Zusammenfassung
This report addresses several questions regarding the deactivation of alumina in catalytic epoxidation using aqueous 70% H2O2. The structural, textural, morphological, and chemical changes of a polycrystalline alumina (γ-Al2O3 and boehmite) were studied in five consecutives reactions of 24 h. The chemical and physical processes involved in the transformations during alumina recycling are attributed mainly to the presence of water in the reaction mixture. Water plays a dual role in the catalytic system. On the one hand, water may cause deleterious changes of the structure of γ-Al2O3 and its textural properties. On the other hand, the presence of water shifts the adsorption equilibria of the organic molecules (acetic acid, diols, and oligomers), preserving the type Ia AlOH sites, which are active for catalytic epoxidation. In this way, the water in the alumina/H2O2 catalytic system seems to be significant in prolonging the lifetime of the catalyst.