KINETICS OF THE DEHYDRATION OF THE BETA-CAGES OF SODIUM FAUJASITES AS STUDIED BY H-NMR SPECTROSCOPY

被引：2

作者：

BASLER, WD ^{[1
]}

LECHERT, HT ^{[1
]}

CARBOO, D ^{[1
]}

KNOCHEL, A ^{[1
]}

机构：

[1] UNIV HAMBURG,INST ANORGAN CHEM,W-2000 HAMBURG 13,GERMANY

来源：

BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 1992年 / 96卷 / 04期

关键词：

ADSORPTION; CRYSTALS; DIFFUSION; SPECTROSCOPY; NUCLEAR MAGNETIC RESONANCE; ZEOLITES;

D O I：

10.1002/bbpc.19920960406

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 kinetics of the dehydration of the beta-cages of sodium faujasites have been studied by NMR methods. For Na-Y type (Si/Al>2) the rate of passing from the beta-cages into the supercages is slow and only weakly dependent on temperature (activation energy E(A) = 4.1 kJ/mol). This is in contrast to the strongly temperature dependent (E(a) = 100 kJ/mol) rate of penetration from the supercages into the beta-cages. A model is proposed assuming the formation of a water-ion complex. The slow rate is explained by a negative complex formation entropy (-40R) due to spatial constraints in the beta-cages. The activation energy is small because the enthalpy of the penetration is nearly canceled by the negative complex formation enthalpy.

引用

页码：545 / 549

页数：5

共 14 条

[1]

BARRER RM, 1959, J PHYS CHEM SOLIDS, V12, P130

[2]

Basler W.D., 1979, PROPERTIES APPLICATI, P174

[3] NMR-SPECTROSCOPIC EVIDENCE OF 2 WATER REGIONS IN ZEOLITES OF FAUJASITE-TYPE [J].

BASLER, WD ;

LECHERT, H ;

KACIREK, H .

BERICHTE DER BUNSEN-GESELLSCHAFT-PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 1976, 80 (05) :451-456

[4]

BASLER WD, 1978, PHYS CHEM, V82, P1051

[5]

BASLER WD, 1977, ACS SYM SER, V40, P335

[6]

BASLER WD, 1976, ACS SYM SER, V34, P291

[7] MECHANISM AND KINETICS OF ISOTOPIC EXCHANGE IN ZEOLITES .2. EXPERIMENTAL DATA [J].

BROWN, LM ;

SHERRY, HS .

JOURNAL OF PHYSICAL CHEMISTRY, 1971, 75 (25) :3855-&

[8] MOLECULAR-MOTION IN ZEOLITE SORBENDS, STUDIED BY VARIOUS NMR METHODS [J].

LECHERT, H ;

BASLER, WD .

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 1989, 50 (05) :497-521

[9]

Mortier W.J., 1982, COMPILATION EXTRA FR

[10] KINETICS OF SURFACE-REACTIONS FROM NUCLEAR MAGNETIC-RESONANCE RELAXATION-TIMES .2. REACTION OF WATER WITH SURFACE COMPLEX IN ZEOLITE 13-X [J].

MURDAY, JS ;

PATTERSON, RL ;

RESING, HA ;

THOMPSON, JK ;

TURNER, NH .

JOURNAL OF PHYSICAL CHEMISTRY, 1975, 79 (24) :2674-2687

← 1 2 →