Proton mobility in H-ZSM5 studied by impedance spectroscopy

被引:63
作者
Franke, ME [1 ]
Simon, U [1 ]
机构
[1] Univ Essen Gesamthsch, Inst Inorgan Chem, D-45127 Essen, Germany
关键词
impedance spectroscopy; zeolites; proton mobility; hopping conductivity;
D O I
10.1016/S0167-2738(98)00436-6
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The electrical properties of dehydrated zeolite H-ZSM5 with different SiO2/Al2O3 ratios (30, 50, 80, 150, 280, and 1000) were examined by complex impedance spectroscopy. We determined the activation energy for proton relaxation, which depends an the spatial distance of the aluminum sites. Classical hopping theory as well as Debye-Huckel theory are in agreement with the experimental data implying that the relaxation originates from translational proton hopping instead of local reorientational motion, as assumed from H-1-MAS-NMR as well as from quantum-chemical calculations. (C) 1999 Elsevier Science BN; All rights reserved.
引用
收藏
页码:311 / 316
页数:6
相关论文
共 32 条
[21]   PROPERTIES OF NA IONS IN NAZSM-5 ZEOLITE [J].
OHGUSHI, T ;
KAWANABE, Y .
ZEOLITES, 1994, 14 (05) :356-359
[22]   QUANTUM-CHEMICAL STUDIES OF ACID SITES IN ZEOLITE ZSM-5 [J].
REDONDO, A ;
HAY, PJ .
JOURNAL OF PHYSICAL CHEMISTRY, 1993, 97 (45) :11754-11761
[23]   IONIC TRANSPORT IN SUPER IONIC CONDUCTORS - THEORETICAL MODEL [J].
RICE, MJ ;
ROTH, WL .
JOURNAL OF SOLID STATE CHEMISTRY, 1972, 4 (02) :294-+
[24]   MOBILITY OF THE ACIDIC PROTON IN BRONSTED SITES OF H-Y, H-MORDENITE, AND H-ZSM-5 ZEOLITES, STUDIED BY HIGH-TEMPERATURE H-1 MAS NMR [J].
SARV, P ;
TUHERM, T ;
LIPPMAA, E ;
KESKINEN, K ;
ROOT, A .
JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (38) :13763-13768
[25]   BRONSTED SITES IN ZEOLITIC CATALYSTS - AN ABINITIO STUDY OF LOCAL GEOMETRIES AND OF THE BARRIER FOR PROTON JUMPS BETWEEN NEIGHBORING SITES [J].
SAUER, J ;
KOLMEL, CM ;
HILL, JR ;
AHLRICHS, R .
CHEMICAL PHYSICS LETTERS, 1989, 164 (2-3) :193-198
[26]  
SAUER J, 1998, IN PRESS ACS S TRANS
[27]   Evidence by ac-conductivity for the higher mobility of boron (over aluminium)-associated Bronsted sites in boron-modified HZSM-5 [J].
Sayed, MB .
MICROPOROUS MATERIALS, 1996, 6 (04) :181-188
[28]   The effect of NH3 on the ionic conductivity of dehydrated zeolites Na beta and H beta [J].
Simon, U ;
Flesch, U ;
Maunz, W ;
Muller, R ;
Plog, C .
MICROPOROUS AND MESOPOROUS MATERIALS, 1998, 21 (1-3) :111-116
[29]   IMPEDANCE-SPECTROSCOPIC STUDIES ON ZEOLITES WITH INCLUDED METAL-CLUSTERS [J].
SIMON, U ;
MOHRKE, C ;
SCHON, G .
CHEMIE INGENIEUR TECHNIK, 1995, 67 (05) :583-&
[30]  
SIMON U, 1999, IN PRESS N POROUS MA