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ESR study of H2O− radicals trapped in Y-type zeolites

✍ Scribed by Antoine Abou-Kaïs; Jacques C. Vedrine

Publisher
Elsevier Science
Year
1977
Tongue
English
Weight
304 KB
Volume
45
Category
Article
ISSN
0009-2614

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✦ Synopsis

A new ESR signal has been observed in y-irradiated Y-type zeolite, the Naf ions of which have been exchanged by divalent cations such as Mgzf or Ca*+. Its ESR parameters are as follows: gt = 2.0065,ga = 2.0060 andgs = 2.0021 k 0.0002 and Ct = 41. C2 = 42.5 and C3 = 73 + 0.5 Oe for hlgY samples andgr = 2.0063.g2 = 2.0060 andg3 = 2.0021* 0.0002 and Ct = 40, C2 = 42 and Ca = 74 t 0.5 Oe for CaY samples. The signal is 3 triplet and the corresponding hyperfine structure 1s shown to be due to the interaction with two hydrogen nuclei. The signal is assigned to an HaO-ion adsorbed on the divalent catron and formed according to the reaction: Me(OH)+ + H' -Me*+ .._ (HaO)-. The &!e(OH)+ corresponds to the 3685 cm-' IR band and the H atom to the ESR doublet with 1.4 Oe linewid?h arising from structural acidic OH groups giving the 3550 cm-' IR band.

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