| Title of Article |
Characterization and temperature evolution of iron-containing
species in HZSM-5 zeolite prepared from different iron sources |
| Date of Acceptance |
3 January 2019 |
| Journal |
| Title of Journal |
Journal of Porous Materials |
| Standard |
SCOPUS |
| Institute of Journal |
Springer Science+Business Media, LLC, part of Springer Nature 2019 |
| ISBN/ISSN |
|
| Volume |
2019 |
| Issue |
26 |
| Month |
january |
| Year of Publication |
2019 |
| Page |
1227–1240 |
| Abstract |
Iron-containing HZSM-5 zeolites are materials with important industrial applications as catalysts. Their characterization is
difficult due to the various possible Fe-containing species which can exist in the pores of HZSM-5 zeolites and their dependence on the preparation technique. Three Fe–HZSM-5 samples were prepared by ion-exchange technique using different
iron precursors: containing only Fe2+ or Fe3+ ions, and containing equimolar mixture of Fe2+ and Fe3+ ions. The samples
were characterized by various experimental techniques (XRD, FTIR, UV–Vis spectroscopy and XANES/EXAFS) in order
to clarify the type of the Fe-containing species existing in the samples. Periodic density functional calculations were also
performed to help in elucidation of the obtained structural information with the EXAFS data and in clarification of the relative stability of the various Fe-containing species in the pores of the HZSM-5 zeolites. In the samples prepared with only
Fe2+ or Fe3+ ions dominate isolated iron species but binuclear FeOFe2+ species and small iron oxide clusters are also present.
In the third sample, prepared from a precursor containing iron ions in both oxidation states, most of the iron is included in
the iron oxide clusters or small nanoparticles. The time-resolved XAS for the sample containing equimolar Fe2+ and Fe3+
ions revealed existence of two types of dominant iron oxide species—small oligonuclear clusters in the temperature region
100–300 °C and larger more oxidized moieties (nanoparticles) after heating the sample up to 400 and 500 °C. |
| Keyword |
DFT · Density functional modeling · Zeolite · EXAFS · Quantum-chemical calculations · UV–Vis |
| Author |
|
| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
true |
| Part of thesis |
true |
| Attach file |
|
| Citation |
0
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Publication
Journal Publication
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