100-18-5Relevant articles and documents
Direct synthesis of carbon-templating mesoporous ZSM-5 using microwave heating
Koo, Jeong-Boon,Jiang, Nanzhe,Saravanamurugan, Shunmugavel,Bejblova, Martina,Musilova, Zuzana,Cejka, Jiri,Park, Sang-Eon
, p. 327 - 334 (2010)
Carbon-templated mesoporous ZSM-5 zeolites were synthesized directly avoiding a drying process. Carbon nanoparticles were simply mixed into synthesis precursor of ZSM-5 and hydrothermally treated by microwave irradiation. The amount of mesopores formed inside the ZSM-5 single crystals was controllable by adjusting the amount of carbon used. For comparison, mesoporous ZSM-5 zeolites have also been synthesized under hydrothermal conditions. The influence of microwave irradiation on mesoporous ZSM-5 materials was thoroughly investigated by using nitrogen adsorption/desorption studies and 27Al MAS NMR. The nature of acid sites both in the micropores (internal) and on the surface of mesopores (external) was investigated by in situ FTIR spectroscopy using pyridine (Py) and 2′,6′-di-tert-butylpyridine (DTBPy) as a probe molecules. Mesoporous ZSM-5 prepared by microwave synthesis showed higher catalytic activity in the bulky molecular reaction of 2′,4′- dimethoxyacetophenone (2′,4′-DMAP) with 4-methoxybenzaldehyde as a model reaction in comparison with the results obtained over hydrothermally prepared ZSM-5. The further catalytic behavior has been studied in condensation reaction and cracking of substituted benzene.
In situ synthesis, characterization of SiPMo-X, and different catalytic properties of SiPMo-X and SiPW-X
Shi, Chunfeng,Wang, Runwei,Zhu, Guangshan,Qiu, Shilun,Long, Jun
, p. 3054 - 3060 (2006)
SBA-15 frameworks with encapsulated Keggin type heteropolyacids (HPAs) were synthesized in situ under strongly acidic conditions (pH 2 adsorption-desorption isotherms and transmission electron microscopy (TEM), and their structure was systematically characterized by X-ray diffraction (XRD), UV/Vis diffuse reflectance-(DRS), infrared- (IR), and 31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Characterization results suggest that the samples show very ordered hexagonal mesostructure, and the HPAs that are incorporated into the framework of meso-silica are insoluble during catalysis. Results of catalytic tests indicate that the materials demonstrated catalytic activity comparable with or even surpassing those of the bulk HPAs in catalytic tests implementing chemical reactions of bulky molecules (1,3,5-tri-isopropylbenzene cracking, esterification of benzoic acid with tert-butyl alcohol, and 2,3,6-trimethylphenol hydroxylation with H 2O2). Additionally, some other properties, such as easy separation and stability when recycled, ensure their potential applications in the chemical industries. Here, we report not only the in situ synthesis and characterization of SiPMo-X, but also the difference in the catalytic properties of SiPMo-X and SiPW-X. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Alkylation of benzene with short-chain olefins over MCM-22 zeolite: Catalytic behaviour and kinetic mechanism
Corma,Martinez-Soria,Schnoeveld
, p. 163 - 173 (2000)
Cumene and ethylbenzene are important compounds in the petrochemical industry for the production of phenol and styrene, respectively. Cumene and ethylbenzene are produced by benzene alkylation with propylene and ethylene. Benzene alkylation with ethylene
Influence of mesoporous materials containing ZSM-5 on alkylation and cracking reactions
Odedairo,Balasamy,Al-Khattaf
, p. 21 - 36 (2011)
In order to increase the yield of cymene in alkylation of toluene with isopropanol, ZSM-5 zeolite units were incorporated into a mesostructured material. The catalysts were characterized by X-ray diffraction, TGA, SEM, NH3 temperature-programmed desorption and FTIR of pyridine adsorption. XRD analysis indicated that a structurally well ordered cubic MCM-48 aluminosilicate was successfully assembled from ZSM-5 zeolite seeds. The ZSM-5/MCM-48 catalyst exhibited significantly improved toluene conversion and yield of cymene product for toluene isopropylation. Catalytic tests show that the ZSM-5/MCM-48 composite material exhibits high catalytic activity compared with the conventional Y-zeolite for catalytic cracking of 1,3,5- triisopropylbenzene (TIPB). The exceptional catalytic performance of ZSM-5/MCM-48 catalyst in cracking and alkylation reaction was attributed to the easier access of active sites provided by the mesopores for both reactant and larger product molecules. The apparent activation energies for the cracking of 1,3,5-TIPB over ZSM-5/MCM-48 catalyst were found to decrease as follows: E C/CM-3 (tertiary cracking) > E C/CM-4 (disproportionation) > E C/CM-2 (secondary cracking) > E C/CM-1 (primary cracking).
A mesoporous aluminosilicate prepared by simply coating fibrous γ-AlOOH on the external surface of SBA-15 for catalytic hydrocarbon cracking
Shi, Zongbo,Guan, Yejun,Wu, Peng,He, Mingyuan
, p. 40296 - 40303 (2016)
A binary SiO2/Al2O3 composite with fibrous γ-alumina coating on the external surface of SBA-15 has been synthesized by simply mixing SBA-15 with fibrous boehmite sol, followed by aging and calcination. The textural and aci
Catalytic cracking of large molecules over hierarchical zeolites
Lei, Qian,Zhao, Tianbo,Li, Fengyan,Zhang, Ling,Wang, Yue
, p. 1769 - 1771 (2006)
A hierarchical zeolite catalyst was synthesized by transforming the skeletons of a bimodal pore silica gel into a zeolite through a steam-assisted conversion method, and shows high catalytic activity and a long catalyst lifetime for catalytic cracking of large molecules. The Royal Society of Chemistry 2006.
Isopropylation of Benzene with 2-Propanol over High-Silica Large-Pore Zeolite: NCL-1
Sasidharan, M.,Reddy, K. Ramesh,Kumar, Rajiv
, p. 216 - 221 (1995)
The influence of various reaction parameters such as temperature, WHSV, time on stream, and feed ratio of benzene to 2-propanol, as well as of the Si/Al molar ratio of zeolite NCL-1, on catalytic activity and selectivity was studied in the isopropylation
Benzene reduction in gasoline by alkylation with olefins: Comparison of Beta and MCM-22 catalysts
Laredo, Georgina C.,Castillo, J. Jesus,Navarrete-Bola?os, Juan,Perez-Romo, Patricia,Lagos, Flavio A.
, p. 140 - 148 (2012)
The study compares the performance of Beta and MCM-22 zeolites as catalysts for propylene alkylation of benzene present in an enriched sample of reformate heart cut (20 wt% benzene). The experiments were carried out in a batch system with a 2/1 mole ratio
Mesoporous mordenites obtained by sequential acid and alkaline treatments - Catalysts for cumene production with enhanced accessibility
Van Laak, Adri N.C.,Sagala, Sophia L.,Zecevic, Jovana,Friedrich, Heiner,De Jongh, Petra E.,De Jong, Krijn P.
, p. 170 - 180 (2010)
Two commercially available mordenites, obtained from Zeolyst (Si/Al = 10 at/at) and BASF (Si/Al = 8 at/at), were subjected to post-synthesis treatments. The impact of acid treatment, alkaline treatment (desilication) and a combination of both on porosity,
A facile approach for the preparation of tunable acid nano-catalysts with a hierarchically mesoporous structure
Choi, Youngbo,Yun, Yang Sik,Park, Hongseok,Park, Dae Sung,Yun, Danim,Yi, Jongheop
, p. 7652 - 7655 (2014)
A facile and efficient approach to prepare hierarchically and radially mesoporous nano-catalysts with tunable acidic properties has been successfully developed. The nanospheres show excellent catalytic performance for the acid catalysed reactions, i.e. cr
