The effects on the local environment of metal centres in Ti- and Fe-silicalites, induced by a vacuum treatment and by subsequent NH3 dosage, has been studied by means of XANES and UV-vis spectroscopies. The Ti(TV) environment is mainly tetrahedral in vacuo and becomes octahedral after interaction with NH3. Fe(III) is in tetrahedral coordination in presence of adsorbates, while in vacuo it is in a distorted tetrahedral symmetry. These conclusions are qualitatively supported by IR and Raman data.
XANES study of Ti and Fe substituted silicalites in presence and in absence of NH3 and comparison with UV-Vis, IR and Raman spectra
BORDIGA, Silvia;LAMBERTI, Carlo;ZECCHINA, Adriano;
1995-01-01
Abstract
The effects on the local environment of metal centres in Ti- and Fe-silicalites, induced by a vacuum treatment and by subsequent NH3 dosage, has been studied by means of XANES and UV-vis spectroscopies. The Ti(TV) environment is mainly tetrahedral in vacuo and becomes octahedral after interaction with NH3. Fe(III) is in tetrahedral coordination in presence of adsorbates, while in vacuo it is in a distorted tetrahedral symmetry. These conclusions are qualitatively supported by IR and Raman data.File in questo prodotto:
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