Evolution of Fe3+ from framework to extra-framework species in Fe-silicate as a function of the template burning temperature

被引：4

作者：

Bordiga, S

Scarano, D

Lamberti, C

Zecchina, A

Geobaldo, F

Vlaic, G

Buzzoni, R

Tozzola, G

Petrini, G

机构：

[1] POLITECN TORINO, DIPARTIMENTO SCI MAT & INGN CHIM, TURIN, ITALY

[2] ENICHEM SPA, CTR RIC NOVARA, NOVARA, ITALY

[3] DIPARTIMENTO SCI CHIM & SINCROTRONE TRIESTE SCPA, TRIESTE, ITALY

来源：

JOURNAL DE PHYSIQUE IV | 1997年 / 7卷 / C2期

关键词：

D O I：

10.1051/jp4:1997275

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report a XAFS study of the Fe3+ local environment in Fe-silicalite as a function of the template burning temperature. We investigate the structural changes of the zeolitic structure, upon thermal treatments and interaction with NH3 Our XAFS results show that, before template burning, Fe3+ are in tetrahedral symmetry with 4 oxygens at 1.85 Angstrom, while after template removal and in vacuum conditions, they exhibit a distorted tetrahedral symmetry with 3 oxygens at 1.87 Angstrom, and one at 2.10 Angstrom; dosage of NH3 partially restore the tetrahedral symmetry of the site. These results are strongly supported by parallel IR, Raman, UV-Vis, TPR and EPR investigations and by recent theoretical simulations.

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收藏

页码：907 / 908

页数：2

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