Effect of Defect Site Preorganization on Fe(III) Grafting and Stability: A Comparative Study of Delaminated Zeolite vs Amorphous Silica Supports
| Autor: | Fernande Grandjean, Alexander Okrut, Stacey I. Zones, Alexander Katz, Dianne J. Xiao, Gary J. Long, Alexander J. Yeh, Nicolás A. Grosso-Giordano |
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| Rok vydání: | 2017 |
| Předmět: |
inorganic chemicals
Thermogravimetric analysis Aqueous solution Materials science 010405 organic chemistry General Chemical Engineering Inorganic chemistry General Chemistry 010402 general chemistry 01 natural sciences 0104 chemical sciences law.invention Amorphous solid Absorption band law Materials Chemistry Calcination Thermal stability Absorption (chemistry) Zeolite |
| Zdroj: | Chemistry of Materials. 29:6480-6492 |
| ISSN: | 1520-5002 0897-4756 |
| Popis: | The stabilization of isolated grafted Fe3+ sites on siliceous supports is investigated by a comparative study of crystalline versus amorphous materials. Our synthetic approach treats crystalline delaminated zeolite DZ-1 and amorphous silica (SiO2) with an aqueous NaFeEDTA cation precursor complex, to result in grafting of isolated Fe3+ sites via covalent attachment to support hydroxyl groups. Thermogravimetric analysis and UV–visible spectroscopy demonstrate the complete detachment of chelating EDTA ligand upon Fe3+ grafting on both supports. Before calcination treatment, both Fe/DZ-1 and Fe/SiO2 have similar UV–visible spectral features, with absorption bands at 208–225 and 257 nm, characteristic of framework Fe3+ sites in zeolites. Calcination does not affect the UV–visible spectroscopic characteristics of Fe/DZ-1 but changes the spectrum of Fe/SiO2 to a single absorption band at 260 nm, indicating better thermal stability of Fe3+ sites in Fe/DZ-1 as compared to Fe/SiO2. This stability persists for Fe/D... |
| Databáze: | OpenAIRE |
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