Characterization of zeolite acidity. II. Measurement of zeolite acidity by ammonia temperature programmed desorption and FTi.r. spectroscopy techniques

The Ammonia Temperature Programmed Desorption (NH 3— TPD) technique has been used to study the acidity of six zeolite samples. The results indicate that, in general, three desorption peaks are observed. The three peaks fall in the temperature regions of; less than 473 K, 473–673 K, and higher than 6...

Full description

Saved in:
Bibliographic Details
Published in:Zeolites 1986-05, Vol.6 (3), p.185-194
Main Authors: Lok, B.M., Marcus, B.K., Angell, C.L.
Format: Article
Language:English
Subjects:
acidity
Catalysis
Catalysts: preparations and properties
Catalytic reactions
Chemistry
Exact sciences and technology
FTi.r
General and physical chemistry
General. Nomenclature, chemical documentation, computer chemistry
Theory of reactions, general kinetics
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
TPD
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Ammonia Temperature Programmed Desorption (NH 3— TPD) technique has been used to study the acidity of six zeolite samples. The results indicate that, in general, three desorption peaks are observed. The three peaks fall in the temperature regions of; less than 473 K, 473–673 K, and higher than 673 K. The first desorption peak is believed to be associated with physically adsorbed or weakly chemically adsorbed ammonia molecules; the second peak is NH 3 molecules adsorbed on zeolite hydroxyl groups, and the third peak is associated mainly with dehydroxylation, strong Brönsted acid sites, and/or Lewis acid sites. The additional data provided by the FTi.r. enables interpretation of the NH 3— TPD chromatogram obtained by the electronic microbalance.
ISSN:0144-2449
1873-3115
DOI:10.1016/0144-2449(86)90046-1