Nanoscale redox catalysts: Cr- and Cr,Al-pillared layer clays: Characterization and catalytic activity

✍ Scribed by Imre Kiricsi; Árpád Molnár; István Pálinkó; Ágnes Fudala; János B. Nagy

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 360 KB
• Volume: 101-103
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00295-6

✦ Synopsis

Via the co-hydrolysis of CrCl, and AlCl, in the presence of swollen Na-montmorillonite, pillared layer clays were prepared. The location of chromium in the pillars and in the primary pillaring agent, the Al,,-Keggin ion, was investigated by various methods (mid and far IR and "Al NMR spectroscopies). We found that isomorphous substitution of chromium for aluminium did not occur, rather co-hydrolysis and co-pillaring took place. Upon heat treatment the loss of outer-sphere water and dehydroxylation at higher temperatures resulted in the formation of bulky alumina pillars decorated with chromia species. The resulting material was used in the oxidation of I-phenyl-1-propanol in the presence of tert-butylhydroperoxide as co-oxidant.