The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite
Abstract
The competitive adsorption of aromatic hydrocarbons (benzene, methyl- and ethyl-benzene) and water on FeZSM-5 zeolites have been investigated by means of temperature-programmed desorption coupled with mass spectrometry (TPD/MS). The incorporation of iron in zeolite was done by aqueous ion exchange using dilute solutions of Fe complexes (ferric citrate and ferrous oxalate) and ferric nitrate. Diffuse reflectance UV-Vis spectroscopy and temperature-programmed reduction (TPR) were applied to characterize active sites on investigated zeolites. The existence of different iron species on FeZSM-5 zeolites was revealed. It has been demonstrated that the activity of the Fe exchanged zeolite depends on the iron salt used for ion exchange. The isolated, dispersed ions, which are often considered to be essential for adsorption and catalysis, were obtained with high yield only by ion exchange in the presence of ferrous oxalate. TPD/MS measurements show that aromatic hydrocarbons adsorb on specific,... strong active sites in hydrated zeolites. The binding occurred when organic molecules replace water previously adsorbed at the same sites. Benzene showed non-dissociative adsorption/desorption, while new mass fragments were recorded during methyl-benzene and ethyl-benzene desorption implying their dissociative adsorption/desorption on active sites in hydrated zeolites.
Keywords:
FeZSM-5 zeolite / Aqueous exchange / Aromatic hydrocarbons adsorption / Temperature-programmed desorptionSource:
Reaction Kinetics Mechanisms and Catalysis, 2018, 123, 1, 231-246Publisher:
- Springer, Dordrecht
Funding / projects:
DOI: 10.1007/s11144-017-1275-y
ISSN: 1878-5190
WoS: 000419514200018
Scopus: 2-s2.0-85030106343
Collections
Institution/Community
Poljoprivredni fakultetTY - JOUR AU - Milojević-Rakić, M. AU - Dondur, Vera AU - Damjanović-Vasilić, Ljiljana AU - Rac, Vladislav AU - Rakić, Vesna PY - 2018 UR - http://aspace.agrif.bg.ac.rs/handle/123456789/4737 AB - The competitive adsorption of aromatic hydrocarbons (benzene, methyl- and ethyl-benzene) and water on FeZSM-5 zeolites have been investigated by means of temperature-programmed desorption coupled with mass spectrometry (TPD/MS). The incorporation of iron in zeolite was done by aqueous ion exchange using dilute solutions of Fe complexes (ferric citrate and ferrous oxalate) and ferric nitrate. Diffuse reflectance UV-Vis spectroscopy and temperature-programmed reduction (TPR) were applied to characterize active sites on investigated zeolites. The existence of different iron species on FeZSM-5 zeolites was revealed. It has been demonstrated that the activity of the Fe exchanged zeolite depends on the iron salt used for ion exchange. The isolated, dispersed ions, which are often considered to be essential for adsorption and catalysis, were obtained with high yield only by ion exchange in the presence of ferrous oxalate. TPD/MS measurements show that aromatic hydrocarbons adsorb on specific, strong active sites in hydrated zeolites. The binding occurred when organic molecules replace water previously adsorbed at the same sites. Benzene showed non-dissociative adsorption/desorption, while new mass fragments were recorded during methyl-benzene and ethyl-benzene desorption implying their dissociative adsorption/desorption on active sites in hydrated zeolites. PB - Springer, Dordrecht T2 - Reaction Kinetics Mechanisms and Catalysis T1 - The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite EP - 246 IS - 1 SP - 231 VL - 123 DO - 10.1007/s11144-017-1275-y ER -
@article{ author = "Milojević-Rakić, M. and Dondur, Vera and Damjanović-Vasilić, Ljiljana and Rac, Vladislav and Rakić, Vesna", year = "2018", abstract = "The competitive adsorption of aromatic hydrocarbons (benzene, methyl- and ethyl-benzene) and water on FeZSM-5 zeolites have been investigated by means of temperature-programmed desorption coupled with mass spectrometry (TPD/MS). The incorporation of iron in zeolite was done by aqueous ion exchange using dilute solutions of Fe complexes (ferric citrate and ferrous oxalate) and ferric nitrate. Diffuse reflectance UV-Vis spectroscopy and temperature-programmed reduction (TPR) were applied to characterize active sites on investigated zeolites. The existence of different iron species on FeZSM-5 zeolites was revealed. It has been demonstrated that the activity of the Fe exchanged zeolite depends on the iron salt used for ion exchange. The isolated, dispersed ions, which are often considered to be essential for adsorption and catalysis, were obtained with high yield only by ion exchange in the presence of ferrous oxalate. TPD/MS measurements show that aromatic hydrocarbons adsorb on specific, strong active sites in hydrated zeolites. The binding occurred when organic molecules replace water previously adsorbed at the same sites. Benzene showed non-dissociative adsorption/desorption, while new mass fragments were recorded during methyl-benzene and ethyl-benzene desorption implying their dissociative adsorption/desorption on active sites in hydrated zeolites.", publisher = "Springer, Dordrecht", journal = "Reaction Kinetics Mechanisms and Catalysis", title = "The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite", pages = "246-231", number = "1", volume = "123", doi = "10.1007/s11144-017-1275-y" }
Milojević-Rakić, M., Dondur, V., Damjanović-Vasilić, L., Rac, V.,& Rakić, V.. (2018). The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite. in Reaction Kinetics Mechanisms and Catalysis Springer, Dordrecht., 123(1), 231-246. https://doi.org/10.1007/s11144-017-1275-y
Milojević-Rakić M, Dondur V, Damjanović-Vasilić L, Rac V, Rakić V. The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite. in Reaction Kinetics Mechanisms and Catalysis. 2018;123(1):231-246. doi:10.1007/s11144-017-1275-y .
Milojević-Rakić, M., Dondur, Vera, Damjanović-Vasilić, Ljiljana, Rac, Vladislav, Rakić, Vesna, "The accessibility of sites active in the dissociative adsorption of aromatic hydrocarbons in FeZSM-5 zeolite" in Reaction Kinetics Mechanisms and Catalysis, 123, no. 1 (2018):231-246, https://doi.org/10.1007/s11144-017-1275-y . .