TEMPERATURE-PROGRAMMED DESORPTION (TPD) OF AMMONIA FROM HZSM-5 ZEOLITES

被引：70

作者：

HUNGER, B ^{[1
]}

HOFFMANN, J ^{[1
]}

HEITZSCH, O ^{[1
]}

HUNGER, M ^{[1
]}

机构：

[1] KARL MARX UNIV,DEPT PHYS,O-7010 LEIPZIG,GERMANY

来源：

JOURNAL OF THERMAL ANALYSIS | 1990年 / 36卷 / 04期

关键词：

D O I：

10.1007/BF01914061

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The temperature-programmed desorption (tpd) of the amount of ammonia which is preadsorbed at about 373 K at HZSM-5 zeolites yields a complex desorption curve consisting of two overlapped peaks (beta and gamma peak). Parts of the ammonia desorbed can be attributed to SiOHA1 groups considering also H-1-MAS NMR measurements. The course of the desorption of both peaks is describable by a rate equation which considers a dependence of the desorption energy on the degree of coverage or an energy distribution, as could be shown by various methods of evaluation. The calculated dependence of the desorption energy on the ammonia amount adsorbed well agrees with data of literature of adsorption heats determined micro-calorimetrically.

引用

页码：1379 / 1391

页数：13

共 38 条

[1] METHODS FOR CHARACTERIZATION AND THEIR INFLUENCE ON THE STRUCTURE OF SILICON-RICH ZEOLITES [J].