Ganguli, Dibyendu and Saha, Prasenjit (1980) Some aspects of ion-exchange and catalytic activity of faujasite type molecular sieve zeolites. Transactions of the Indian Ceramic Society, 39 (2). pp. 57-62. ISSN 0371-750X

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Abstract

Natural and synthetic crystalline zeolites are characterized by frameworks originating from linkages of (Si, Al)-tetrahedra, in which structural cages and channels are occupied by water molecules and an appropriate amount of non· framework cations for balancing the negative charge of the available (AlO2)-groups. Most common among these non-framework cations are Na+, Ca2+and K+(in both natural and as-synthesized zeolites). Reversible and facile exchange of these cations with others is one of the characteristic properties of zeolites. The extents of such exchanges are guided by factors like crystallographic sites and structural openings involved, ionic hydration energies, hydrated radii of the ions etc. Technologically important ion exchanges in zeolites include Ni2+, RE3+(e.g. La3+, Ce3+) and NH4 +for sodium. The present paper discnsses some aspects of the current knowledge on the phenomenon of ion-exchange in zeolites, the important criteria that are involved, and the modifica· tions in properties that follow complete or partial exchange of sodium in synthetic faujasite-type zeolites. Special emphasis has been given on the development of catalytic activity in these zeolites by virtue of ion exchange and subsequent activation. © 1980 Taylor & Francis Group, LLC.

Item Type:	Article
Subjects:	Structural Clay Products
Divisions:	UNSPECIFIED
Depositing User:	Bidhan Chaudhuri
Date Deposited:	25 May 2016 11:27
Last Modified:	25 May 2016 11:27
URI:	http://cgcri.csircentral.net/id/eprint/3413

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