Structure of Al-Lewis Site in Beta Zeolite Active in Meerwein-Ponndorf-Verley Reduction of Ketone to Alcohol

0181543 - UFCH-W 20020175 RIV US eng J - Článek v odborném periodiku
Bortnovsky, O. - Sobalík, Zdeněk - Wichterlová, Blanka - Bastl, Zdeněk
Structure of Al-Lewis Site in Beta Zeolite Active in Meerwein-Ponndorf-Verley Reduction of Ketone to Alcohol.
Journal of Catalysis. Roč. 210, - (2002), s. 171-182. ISSN 0021-9517. E-ISSN 1090-2694
Grant CEP: GA AV ČR IBS4040015
Výzkumný záměr: CEZ:AV0Z4040901
Klíčová slova: Meerwein-Ponndorf-Verley reduction * beta zeolite * Lewis acid
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 3.118, rok: 2002

H-beta zeolites differing in removal of the template by calcination in an oxygen or in a stream of ammonia, and in their subsequent steam treatment at various temperatures, as well as beta zeolites exchanged with alkaline metal ions, were investigated in the MPV reduction of 4-tert-butyl cyclohexanone to 4-tert-butyl hexanol using isopropanol. FTIR of the OH groups, of the C=N groups of adsorbed d(3)-acetonitrile, and of the framework T-O-T antisymmetric mode was used to estimate the concentration of the individual Al-Lewis sites. XPS was employed to monitor the migration of the Al species into the surface layers of the zeolite crystals. The VHF band at 3780 cm(-1) and skeletal T-O-T bands at 901, 890, and 882 cm-1 were found for steam-treated (ST) H-beta. Both alkali metal ion exchange and treatment of zeolite by gaseous ammonia annihilated the bands at 3780 and 882 cm-1, but the bands at 901 and 890 cm-1 (siloxane bridges) were retained. While the bands at 3780 and 882 cm-1.
Trvalý link: http://hdl.handle.net/11104/0078097