APPLICATION OF POSITRON-ANNIHILATION SPECTROSCOPY TO THE STUDY OF ZEOLITES

被引：11

作者：

GAO, Z ^{[1
]}

YANG, X ^{[1
]}

CUI, J ^{[1
]}

YANG, Y ^{[1
]}

机构：

[1] FUDAN UNIV,DEPT PHYS,SHANGHAI,PEOPLES R CHINA

来源：

ZEOLITES | 1991年 / 11卷 / 06期

基金：

中国国家自然科学基金;

关键词：

POSITRON ANNIHILATION SPECTROSCOPY; BRONSTED ACIDITY; ELECTROSTATIC-FIELD GRADIENT; FAUJASITE; MORDENITE;

D O I：

10.1016/S0144-2449(05)80012-0

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：

Positron annihilation lifetime measurements were carried out for various types of zeolites. The lifetime spectra were resolved into four components. The two longer lifetime components are attributed to the annihilation of o-Ps (Ps = positronium atoms) on the surface and in the cages of the zeolites. The o-Ps lifetimes on the surface and in the cages are shortened in the presence of Bronsted acidity due to oxidation reaction between o-Ps and the Bronsted acid sites. The o-Ps annihilation rates of NaHY and NaHM zeolites increase linearly with increasing Bronsted acid site concentration. For faujasites with different cations and Si/Al ratios, the lifetimes of o-Ps decrease with increasing electrostatic-field gradient in the zeolite. Experimental results show that positron annihilation spectroscopy is a useful tool for the characterization of zeolites.

引用

页码：607 / 611

页数：5

共 10 条

[1]

BARRER RM, 1978, ZEOLITES CLAY MINERA, P187

[2]

DEMPSEY E, 1968, MOL SIEVES, P293

[3]

GOLDANSKII VI, 1972, KINET KATAL, V13, P961

[4] POSITRONFIT EXTENDED - NEW VERSION OF A PROGRAM FOR ANALYZING POSITRON LIFETIME SPECTRA [J].