β-MCM41 composite molecular sieves were hydrothermally synthesized using NaOH treated β zeolite as precursors, and Pt/β-MCM41
bifunctional catalysts were prepared by impregnation. Hβ, desilicated Hβ by NaOH treatment (Dβ), and the physical mixture
of Hβ and MCM41 (β+MCM41) were also used as control supports for bifunctional catalysts. All the catalysts were characterized
by ICP, XRD, BET, nitrogen adsorption–desorption isotherm and NH3-TPD, and evaluated in the hydroisomerization of n-heptane using an atmospheric fixed bed flow reactor. Dβ, β+MCM41, or β-MCM41 supported Pt catalysts showed higher selectivity
to isoheptanes than the counterpart Pt/Hβ did due to the presence of mesopores in addition to the zeolite micropores. Moreover,
Pt/β-MCM41 was demonstrated to be a much more selective catalyst among them because the connection between mesopores and micropores
accelerated the diffusion of larger molecules of isoheptanes. Under optimal conditions, Pt/β-MCM41 provided a very high selectivity
to isomerization of 96.5%, coupled with a considerable high conversion of n-heptane of 56.0%.
Authors:A. Garrido Pedrosa, M. Souza, S. Lima, Dulce Melo, A. Souza, and A. Araújo
bifunctional catalysts were synthesized using impregnation and polymeric precursor
methods. After the synthesis process the samples were calcined at 600, 700
and 800C and characterized by X-ray diffraction, nitrogen adsorption
and temperature programmed reduction study by thermogravimetry. DTG-TPR profiles
showed between three and five reduction events at different temperatures attributed
to platinum reduction and to different stages of tungsten species reduction.
A comparative study of the synthesis method influence on the DTG-TPR curves
Authors:Yue Yao, Jianhong Wang, Yanyan Deng, and Jun Wang
(C 7 –C 9 ) is also very important because of the much higher octane number of the corresponding isoparaffins, wherein n -heptane is usually used as a model reactant for fundamental research [ 1 , 2 ]. Since the commercial bifunctionalcatalyst Pt
Authors:Ahcène Soualah, Jean-Louis Lemberton, Ludovic Pinard, Mohamed Chater, Patrick Magnoux, and Kjell Moljord
Hydroisomerization and hydrocracking of n -paraffins are important reactions in refinery processes for the production of high quality fuels employing bifunctionalcatalysts. These catalysts comprised of a metal
Authors:Angela Martins, João M. Silva, Fernando Râmoa Ribeiro, and M. Filipa Ribeiro
branching of the carbon chain. The reaction is carried out over bifunctionalcatalysts, containing small metal particles such as Pt or Pd dispersed on an acid support. According to the bifunctional mechanism, n-alkenes resulting from the dehydrogenation of
Authors:Ping Liu, Xingguang Zhang, Yue Yao, and Jun Wang
Alkaline earth metal (Mg, Ca, Sr and Ba) ions were exchanged into Hβ zeolite, which were used as the supports to load the
noble metal Pt to prepare bifunctional catalysts for hydroisomerization of n-heptane. The catalysts were characterized by ICP, XRD, BET, NH3-TPD, H2-TPR and H2-chemisorption techniques, and evaluated in an atmospheric fixed bed reactor. The catalysts promoted by the alkaline earth
metals are revealed to present much higher selectivity to isomerization than the counterpart Pt/Hβ. Moreover, the Ba-bearing
catalyst loaded with 0.4 wt% Pt and 5:1 molar ratio of Ba to Pt gives a very high selectivity to iso-heptanes 95.4% with a
considerable high conversion of n-heptane 61.7%. The promotion effect of alkaline earth metals is briefly discussed in relation to characterization data.
Authors:N. Batalha, L. Pinard, S. Morisset, J. L. Lemberton, Y. Pouilloux, M. Guisnet, F. Lemos, and F. R. Ribeiro
the rather low Pt/ZSM-22 activity. In contrast, all the acid sites of bifunctionalcatalysts containing large pore zeolites are accessible and their hydroisomerization activity is very high, but often at the expense of the selectivity to isomers [ 17
-range alkanes with bifunctionalcatalysts ” Peng , B. , Yao , Y. , Zhao , C. , Lercher , J. A. Angewandte Chemie International Edition 2012 , 51 , 2072 – 2075 .
“ Triphase microfluidic-directed self-assembly: Anisotropic