N2 and CO as probe molecules for determining the properties of acid sites on the surface of zeolites

The applicability of molecular nitrogen as a probe for the Brønsted and Lewis acid sites of HNaY and HZSM-5 zeolites was studied by Fourier transform IR spectroscopy. The integrated absorption coefficients of bands due to N—N vibrations in complexes with Brønsted and Lewis acid sites were determined. The correlation between the integrated absorption coefficients and the positions of bands due to N—N vibrations in nitrogen interacting with the acid sites of test samples is discussed. We propose using the low-temperature adsorption of nitrogen for express determination of the concentrations of strong Lewis and Brønsted acid sites in zeolites.Translated from Kinetika i Kataliz, Vol. 46, No. 1, 2005, pp. 108–114.Original Russian Text Copyright © 2005 by Malyshev, Paukshtis, Malysheva, Toktarev, Vostrikova.