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Free keywords:
NaY zeolite; IR; Research context: zeolites
Abstract:
RuNaY zeolitenext term was prepared by ion exchange of NaY with an aqueous solution of [Ru(NH3)6]Cl3. The resulting complex was decomposed and reduced. The IR spectra of CO adsorbed at 110 K on the highly dispersed Ru o clusters inside the supercages (1–1.5 nm) and on the sintered clusters at the external surface (5.5, 10–15 and 30 nm) display a broad band at not, vert, similar 2040 cm−1 and a low frequency shoulder at not, vert, similar 2000 cm−1. The former corresponds to linearly bonded CO species and the latter to CO adsorbed on the Ru atoms with low coordination numbers. The autoreduced sample produced an additional shoulder at 2098 cm−1 which is assigned to the CO species weakly σ-bonded to the residual Ru x+ ions in the zeolite or to CO adsorbed on single ru atoms perturbed by surrounding oxygen atoms. The band width was found to be sensitive to reduction conditions and hence particle sizes.