TG/DTG/DTA Study on Interaction between the Framework of High Silica Hydrophobic FAU Zeolite and Adsorbed Organics

• Published in: Langmuir Vol. 15; no. 16; pp. 5382 - 5388
• Main Authors: Yang, Hu, Ping, Zhenghua, Niu, Guoxin, Jiang, Huiwen, Long, Yingcai
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03.08.1999
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Ion-exchange; Surface physical chemistry; Zeolites: preparations and properties; Intermolecular interaction; Thermogravimetric analysis; Molecular structure; Organic adsorbate; Thermogravimetry; Adsorption capacity; Differential thermal analysis; Zeolite; Molecular sieve
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la981626u

High silica hydrophobic FAU zeolite with perfect framework was prepared and used to study the interaction between the framework and 25 adsorbed organic compounds with TG/DTG/DTA. The compounds studied were hydrocarbons, alcohols, organic acids, chloro-containing organics, alkylamines, and esters. The saturating capacities of adsorption were measured. The affinity index A T was determined and used to evaluate the interaction between the framework of the zeolite and the adsorbates. Different A T value reveals unlike interaction. The Si−O−Si framework of the zeolite shows a stronger affinity with saturated hydrocarbons than with unsaturated ones, and usually phobic with the alkylalcohols and organic acids. The special sorbate/framework and sorbate/sorbate interactions for certain organics, such as amines, can be identified from the very high A T values, the double peaks in the DTG curves, and thermal effects in the DTA curves. The tendency of A T values for the adsorbed organic species on high silica hydrophobic FAU zeolite is similar to that on high silica hydrophobic MFI zeolite. An index of S T, the adsorption density on the framework, is higher for MFI zeolite than for FAU zeolite, leading to the lower A T value of a certain adsorbate on FAU zeolite than on MFI zeolite.