Adsorption Properties of Aluminophosphate Molecular Sieves with AEL and AFI Structures According to Gas Chromatography Data

• Published in: Russian Journal of Physical Chemistry A 2024-07, Vol.98 (7), p.1372-1379
• Main Authors: Balandina, K. S., Agliullin, M. R., Gus’kov, V. Yu, Vakulin, I. V.
• Format: Article
• Language: English
• Subjects: Alcohols; All-Russian Conference “Surface Phenomena in Dispersed Systems”; Aluminum phosphate; Aromatic compounds; Benzene; Chemistry; Chemistry and Materials Science; Gas chromatography; Internal energy; Molecular sieves; Molecular structure; Organic compounds; Physical Chemistry; Selective adsorption; Toluene; Xylene
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024424700365

The adsorption properties of zeolite-like materials—aluminophosphate molecular sieves AFI and AEL—with respect to a wide range of organic compounds were studied using reversed gas chromatography. The specific retention volumes were obtained, and the molar changes in the internal energy and entropy during adsorption were calculated. The samples are capable of structure-selective adsorption. A molecular sieve effect was found for arenes and n -alcohols. On the AFI sample, the specific retention volume for ortho -xylene is smaller than for toluene. On the AEL sample, the retention of arenes varies in the series: toluene < benzene < xylenes. An analysis of the thermodynamic characteristics of adsorption shows that the additivity of adsorption heats in the homologous series is violated. This indicates the presence of pores in the aluminophosphate molecular sieves. The obtained tendencies in the adsorption of organic compounds can be used for adsorption and catalytic processes involving the studied materials.