Clays and Clay Minerals, Vol. 54, No. 1, 54-61, 2006.
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Authors
Jagtap, Neelam
Ramaswamy, Veda
Issue Date
2006
Type
Article
Language
en_US
Keywords
Periodicals , Geology , Al-PILC , Co Phthalocyanine , Encapsulated Co-complex , Ultrasonification
Alternative Title
Encapsulation of Co Phthalocyanine in Alumina-pillared Clays and their Characterization
Abstract
Alumina-pillared montmorillonite clays (Al-PILC), prepared under ultrasonic (US) agitation and normal stirring (S) methods, have been used as a host material to encapsulate Co phthalocyanine (CoPc) complex. The amount of Co varies from 0.27 to 1.48 wt.% in the samples, depending on the input concentration of Co. Powder X-ray diffraction and other characterization techniques reveal that the structure of Al-PILC remains intact after the incorporation of the complex into the pores through a pyridine solution of the complex by ultrasonic agitation. A substantial decrease in the BET surface area and total pore volume of Al-PILC points to the occupation of the CoPc moieties within the porous structure of the pillared clay. This is further supported by the observation of a band at 1489 cmÿ1 in the Fourier transform infrared (FTIR) spectra of the encapsulated samples. The FTIR and diffuse reflectance ultraviolet-visible (DRUV-Vis) spectral results indicate that the encapsulated CoPc complex in the clay matrix undergoes distortion in order to accommodate itself within the pores of the Al-PILC. The encapsulated samples prepared by ultrasonification show better dispersion of the complex than the samples prepared under normal stirring conditions. Compared to the `neat' complex, the encapsulated samples (CoPc in Al-PILC) exhibit greater turnover in the test reaction of the oxidation of benzyl alcohol to benzaldehyde with tert- butyl hydroperoxide as the oxidant at 373 K. The method of preparation and consequent site isolation of CoPc in Al-PILC influence the catalytic activity.
Description
Clays and Clay Minerals, Vol. 54, No.01, 54-61, 2006.
Encapsulation of Co Phthalocyanine in Alumina-pillared Clays
and their Characterization
Neelam Jagtap; Veda Ramaswamy
DOI: 10.1346/CCMN.2006.0540107
Copyright © 2006, The Clay Minerals Society
Citation
Clays and Clay Minerals, Vol. 54, No. 1, 54-61, 2006.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018, The Clay Minerals Society