Fractal Dimension of Active-Site Models of Zeolite Catalysts

Torrens, Francisco; Castellano, Gloria

doi:https://doi.org/10.1155/JNM/2006/17052

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Volume 2006 | Article ID 017052 | https://doi.org/10.1155/JNM/2006/17052

Fractal Dimension of Active-Site Models of Zeolite Catalysts

Francisco Torrens¹and Gloria Castellano^2,3

Received20 Mar 2006

Revised31 May 2006

Accepted09 Jun 2006

Published07 Aug 2006

Abstract

A method for the calculation of fractal surfaces of crystals is presented. The fractal dimension D of fragments of zeolites is calculated. Results compare well with reference calculations (GEPOL). The active site of Brønsted acid zeolites is modeled by a set of Al–OH–Si units. These units form 2–12-membered rings. Topological indices for the different active-site models are calculated. The comparison between GEPOL and SURMO2 allows calculating the active-site indices. Most cavities show no fractal character, while for the 6–8-unit rings, D lies in the range 4.0–4.3. The 6-ring shows the greatest D and is expected to be the most reactive.

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Copyright

Copyright © 2006 Francisco Torrens and Gloria Castellano. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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