Influence of the desilication process on the acidity of HZSM-5 zeolite
Abstract
The influence of the alkaline treatment on the acidity of zeolite ZSM-5 (SiO2/Al2O3 = 23, 50 and 80) modified by desilication was investigated. The samples were characterized by X-ray diffraction, low temperature adsorption of nitrogen and solid-state Al-27 MAS NMR. Acidity of the samples was investigated using microcalorimetry-volumetry of ammonia adsorption at 423 K. Acid sites accessibility and intracrystalline diffusion were estimated by the thermokinetic parameter. The desilication process was shown to be Si/Al ratio dependant. Relative enhancement of mesopore surface decreased in the following order of SiO2/Al2O3: 50 >80 >23. Pore size distribution broadened and mesopore sizes increased with increasing Si/Al ratio. For samples with SiO2/Al2O3 = 50 and 80 almost full preservation of acid sites strength and distribution was achieved. Significant alteration of the acidity was found for the mesoporous sample with SiO2/Al2O3 = 23. Thermokinetic parameter values indicate facilitated in...tracristalline diffusion for mesoporous samples.
Keywords:
Hierarchical ZSM-5 / Desilication / Microcalorimetry / Acidity / Thermokinetic parameterSource:
Thermochimica Acta, 2013, 567, 73-78Publisher:
- Elsevier, Amsterdam
Funding / projects:
DOI: 10.1016/j.tca.2013.01.008
ISSN: 0040-6031
WoS: 000323408100012
Scopus: 2-s2.0-84884534924
Collections
Institution/Community
Poljoprivredni fakultetTY - JOUR AU - Rac, Vladislav AU - Rakić, Vesna AU - Miladinović, Zoran AU - Stošić, Dušan AU - Auroux, Aline PY - 2013 UR - http://aspace.agrif.bg.ac.rs/handle/123456789/3289 AB - The influence of the alkaline treatment on the acidity of zeolite ZSM-5 (SiO2/Al2O3 = 23, 50 and 80) modified by desilication was investigated. The samples were characterized by X-ray diffraction, low temperature adsorption of nitrogen and solid-state Al-27 MAS NMR. Acidity of the samples was investigated using microcalorimetry-volumetry of ammonia adsorption at 423 K. Acid sites accessibility and intracrystalline diffusion were estimated by the thermokinetic parameter. The desilication process was shown to be Si/Al ratio dependant. Relative enhancement of mesopore surface decreased in the following order of SiO2/Al2O3: 50 >80 >23. Pore size distribution broadened and mesopore sizes increased with increasing Si/Al ratio. For samples with SiO2/Al2O3 = 50 and 80 almost full preservation of acid sites strength and distribution was achieved. Significant alteration of the acidity was found for the mesoporous sample with SiO2/Al2O3 = 23. Thermokinetic parameter values indicate facilitated intracristalline diffusion for mesoporous samples. PB - Elsevier, Amsterdam T2 - Thermochimica Acta T1 - Influence of the desilication process on the acidity of HZSM-5 zeolite EP - 78 SP - 73 VL - 567 DO - 10.1016/j.tca.2013.01.008 ER -
@article{ author = "Rac, Vladislav and Rakić, Vesna and Miladinović, Zoran and Stošić, Dušan and Auroux, Aline", year = "2013", abstract = "The influence of the alkaline treatment on the acidity of zeolite ZSM-5 (SiO2/Al2O3 = 23, 50 and 80) modified by desilication was investigated. The samples were characterized by X-ray diffraction, low temperature adsorption of nitrogen and solid-state Al-27 MAS NMR. Acidity of the samples was investigated using microcalorimetry-volumetry of ammonia adsorption at 423 K. Acid sites accessibility and intracrystalline diffusion were estimated by the thermokinetic parameter. The desilication process was shown to be Si/Al ratio dependant. Relative enhancement of mesopore surface decreased in the following order of SiO2/Al2O3: 50 >80 >23. Pore size distribution broadened and mesopore sizes increased with increasing Si/Al ratio. For samples with SiO2/Al2O3 = 50 and 80 almost full preservation of acid sites strength and distribution was achieved. Significant alteration of the acidity was found for the mesoporous sample with SiO2/Al2O3 = 23. Thermokinetic parameter values indicate facilitated intracristalline diffusion for mesoporous samples.", publisher = "Elsevier, Amsterdam", journal = "Thermochimica Acta", title = "Influence of the desilication process on the acidity of HZSM-5 zeolite", pages = "78-73", volume = "567", doi = "10.1016/j.tca.2013.01.008" }
Rac, V., Rakić, V., Miladinović, Z., Stošić, D.,& Auroux, A.. (2013). Influence of the desilication process on the acidity of HZSM-5 zeolite. in Thermochimica Acta Elsevier, Amsterdam., 567, 73-78. https://doi.org/10.1016/j.tca.2013.01.008
Rac V, Rakić V, Miladinović Z, Stošić D, Auroux A. Influence of the desilication process on the acidity of HZSM-5 zeolite. in Thermochimica Acta. 2013;567:73-78. doi:10.1016/j.tca.2013.01.008 .
Rac, Vladislav, Rakić, Vesna, Miladinović, Zoran, Stošić, Dušan, Auroux, Aline, "Influence of the desilication process on the acidity of HZSM-5 zeolite" in Thermochimica Acta, 567 (2013):73-78, https://doi.org/10.1016/j.tca.2013.01.008 . .