Influence of the desilication process on the acidity of HZSM-5 zeolite
Apstrakt
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.
Ključne reči:
Thermokinetic parameter / Microcalorimetry / Hierarchical ZSM-5 / Desilication / AcidityIzvor:
Thermochimica Acta, 2013, 567, 73-78Izdavač:
- Elsevier, Amsterdam
Finansiranje / projekti:
- Porozni materijali na bazi oksida u zaštiti životne sredine od genotoksičnih supstanci (RS-MESTD-Basic Research (BR or ON)-172018)
DOI: 10.1016/j.tca.2013.01.008
ISSN: 0040-6031
WoS: 000323408100012
Scopus: 2-s2.0-84884534924
Institucija/grupa
Institut za opštu i fizičku hemijuTY - JOUR AU - Rac, Vladislav AU - Rakić, Vesna AU - Miladinović, Zoran AU - Stosić, Dušan AU - Auroux, Aline PY - 2013 UR - https://riofh.iofh.bg.ac.rs/handle/123456789/268 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 UR - conv_462 ER -
@article{ author = "Rac, Vladislav and Rakić, Vesna and Miladinović, Zoran and Stosić, 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", url = "conv_462" }
Rac, V., Rakić, V., Miladinović, Z., Stosić, 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 conv_462
Rac V, Rakić V, Miladinović Z, Stosić 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 conv_462 .
Rac, Vladislav, Rakić, Vesna, Miladinović, Zoran, Stosić, 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 ., conv_462 .