TY - GEN
T1 - Aromatization of alkanes over Pt promoted conventional and mesoporous gallosilicates of MEL zeolite
AU - Akhtar, M. N.
AU - Al-Yassir, N.
AU - Al-Khattaf, S.
AU - Čejka, Jiří
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): K-C1-019-12
Acknowledgements: The authors would like to express their appreciations to King Abdulaziz City for Science and Technology for their financial support under project No. 12-3MT. The financial support made by King Abdullah University of Science and Technology (KAUST) (Award No. K-C1-019-12) is highly appreciated. The authors would like also to extend their appreciation to the support from King Fahd University of Petroleum and Minerals.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
PY - 2012/1
Y1 - 2012/1
N2 - Aromatization of hexane and propane was investigated over Pt promoted mesoporous gallium-containing HZSM-11 with controlled mesoporosity generated by desilication. Prepared catalysts were characterized by nitrogen adsorption, X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared of chemisorbed pyridine, and NH 3 temperature programmed desorption confirming the development of intracrystalline mesoporosity of Ga-containing HZSM-11. The catalytic activities, which were compared in the aromatization of n-hexane and propane, increased upon desilication. The aromatization of n-hexane decreased in the following order, Pt/mesoporous GaZSM-11 Pt/conventional GaZSM-11 mesoporous GaZSM-11 > conventional GaZSM-11. Hexane conversion reached 70.1% over mesoporous Pt/GaZSM-11 with Si/Ga of 61, as compared with 29.6 and 24.9% for corresponding mesoporous and conventional GaZSM-11 (Si/Ga = 94), respectively, for experiments at liquid hour space velocity of 3.6 h -1, and 540 °C. Comparison of BTX (benzene-toluene-xylene) selectivity at the conversion level of ∼21.0% revealed that Pt/mesoporous GaZSM-11 is more selective than corresponding mesoporous and conventional GaZSM-11. The BTX selectivity over Pt/mesoporous GaZSM-11 (Si/Ga = 94), which showed strong dependence on the conversion, reached 28.2%, whereas over corresponding mesoporous and conventional GaZSM-11catalysts reached 19.1% and 5.5%, respectively. A higher conversion and better selectivity can be attributed to the improved accessibility to the active extra-framework Ga species owing to the generation of mesopores inside the zeolite particles and shortening the contact time. It is worth mentioning that the prepared catalysts exhibited quite low activity in propane aromatization but exhibiting similar trends as for hexane aromatization. © 2011 Elsevier B.V. All rights reserved.
AB - Aromatization of hexane and propane was investigated over Pt promoted mesoporous gallium-containing HZSM-11 with controlled mesoporosity generated by desilication. Prepared catalysts were characterized by nitrogen adsorption, X-ray powder diffraction, scanning electron microscopy, Fourier transform infrared of chemisorbed pyridine, and NH 3 temperature programmed desorption confirming the development of intracrystalline mesoporosity of Ga-containing HZSM-11. The catalytic activities, which were compared in the aromatization of n-hexane and propane, increased upon desilication. The aromatization of n-hexane decreased in the following order, Pt/mesoporous GaZSM-11 Pt/conventional GaZSM-11 mesoporous GaZSM-11 > conventional GaZSM-11. Hexane conversion reached 70.1% over mesoporous Pt/GaZSM-11 with Si/Ga of 61, as compared with 29.6 and 24.9% for corresponding mesoporous and conventional GaZSM-11 (Si/Ga = 94), respectively, for experiments at liquid hour space velocity of 3.6 h -1, and 540 °C. Comparison of BTX (benzene-toluene-xylene) selectivity at the conversion level of ∼21.0% revealed that Pt/mesoporous GaZSM-11 is more selective than corresponding mesoporous and conventional GaZSM-11. The BTX selectivity over Pt/mesoporous GaZSM-11 (Si/Ga = 94), which showed strong dependence on the conversion, reached 28.2%, whereas over corresponding mesoporous and conventional GaZSM-11catalysts reached 19.1% and 5.5%, respectively. A higher conversion and better selectivity can be attributed to the improved accessibility to the active extra-framework Ga species owing to the generation of mesopores inside the zeolite particles and shortening the contact time. It is worth mentioning that the prepared catalysts exhibited quite low activity in propane aromatization but exhibiting similar trends as for hexane aromatization. © 2011 Elsevier B.V. All rights reserved.
UR - http://hdl.handle.net/10754/600097
UR - https://linkinghub.elsevier.com/retrieve/pii/S0920586111005244
UR - http://www.scopus.com/inward/record.url?scp=84655163801&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2011.06.036
DO - 10.1016/j.cattod.2011.06.036
M3 - Conference contribution
SP - 61
EP - 72
BT - Catalysis Today
PB - Elsevier BV
ER -