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.
引用
收藏
页码:907 / 908
页数:2
相关论文
共 15 条
[1]   SYNTHESIS AND CHARACTERIZATION OF FERRISILICATE ZEOLITE OF PENTASIL GROUP [J].
BORADE, RB .
ZEOLITES, 1987, 7 (05) :398-403
[2]   XANES STUDY OF TI AND FE SUBSTITUTED SILICALITES IN PRESENCE AND IN ABSENCE OF NH3 AND COMPARISON WITH UV-VIS, IR AND RAMAN-SPECTRA [J].
BORDIGA, S ;
GEOBALDO, F ;
LAMBERTI, C ;
ZECCHINA, A ;
BOSCHERINI, F ;
GENONI, F ;
LEOFANTI, G ;
PETRINI, G ;
PADOVAN, M ;
GEREMIA, S ;
VLAIC, G .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1995, 97 (1-4) :23-27
[3]   XAFS STUDY OF TI-SILICALITE - STRUCTURE OF FRAMEWORK TI(IV) IN PRESENCE AND IN ABSENCE OF REACTIVE MOLECULES (H2O, NH3) [J].
BORDIGA, S ;
BOSCHERINI, F ;
COLUCCIA, S ;
GENONI, F ;
LAMBERTI, C ;
LEOFANTI, G ;
MARCHESE, L ;
PETRINI, G ;
VLAIC, G ;
ZECCHINA, A .
CATALYSIS LETTERS, 1994, 26 (1-2) :195-208
[4]   XAFS STUDY OF TI-SILICALITE - STRUCTURE OF FRAMEWORK TI(IV) IN THE PRESENCE AND ABSENCE OF REACTIVE MOLECULES (H2O, NH3) AND COMPARISON WITH ULTRAVIOLET-VISIBLE AND IR RESULTS [J].
BORDIGA, S ;
COLUCCIA, S ;
LAMBERTI, C ;
MARCHESE, L ;
ZECCHINA, A ;
BOSCHERINI, F ;
BUFFA, F ;
GENONI, F ;
LEOFANTI, G ;
PETRINI, G ;
VLAIC, G .
JOURNAL OF PHYSICAL CHEMISTRY, 1994, 98 (15) :4125-4132
[5]   Structure and reactivity of framework and extraframework iron in Fe-silicalite as investigated by spectroscopic and physicochemical methods [J].
Bordiga, S ;
Buzzoni, R ;
Geobaldo, F ;
Lamberti, C ;
Giamello, E ;
Zecchina, A ;
Leofanti, G ;
Petrini, G ;
Tozzola, G ;
Vlaic, G .
JOURNAL OF CATALYSIS, 1996, 158 (02) :486-501
[6]   COORDINATION OF IRON IN OXIDE GLASSES THROUGH HIGH-RESOLUTION K-EDGE SPECTRA - INFORMATION FROM THE PRE-EDGE [J].
CALAS, G ;
PETIAU, J .
SOLID STATE COMMUNICATIONS, 1983, 48 (07) :625-629
[7]   STRUCTURE OF IRON-SUBSTITUTED ZSM-5 [J].
LEWIS, DW ;
CATLOW, CRA ;
SANKAR, G ;
CARR, SW .
JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (08) :2377-2383
[8]   COMPUTER-SIMULATION OF FE-ZSM5 - COMPARISON TO EXAFS STUDIES [J].
LEWIS, DW ;
SANKAR, G ;
RICHARD, C ;
CATLOW, CRA ;
CARR, SW ;
THOMAS, JM .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 1995, 97 (1-4) :44-49
[9]  
LYTLE FW, 1989, PHYSICA B, V158, P701
[10]  
MICHALOVICZ A, 1990, THESIS U PARIS VAL M