Synthesis of 10 and 12 Ring Zeolites (MCM-22, TNU-9 and MCM-68) Modified with Zn and Its Potential Application in the Reaction of Methanol to Light Aromatics and Olefins
Por:
Garcia-Ruiz, Misael, Solis-Casados, Dora A., Aguilar-Pliego, Julia, Marquez-Alvarez, Carlos, Sastre-de Andres, Enrique, Sanjurjo-Tartalo, Diana, Sainz-Vaque, Raquel, Grande-Casas, Marisol
Publicada:
1 ago 2020
Resumen:
The effect on the incorporation of zinc of three zeolites TNU-9, MCM-22,
and MCM-68 was investigated. The physico-chemical properties of zeolites
were studied by X-ray diffraction, N-2-adsorption,
temperature-programmed desorption of NH3 (TPD), nuclear magnetic
resonance of Al-27 and Si-29 (MAS NMR), scanning electron microscopy
(SEM) and thermogravimetric analysis (TGA). Then all the samples were
characterized and evaluated in the reaction of methanol to aromatics
(MTA). The correlation of zinc incorporation method and acidic
properties of zeolites with catalytic performance was investigated. The
form of zinc incorporation, the acidity, the type of zeolitic structure
and the reaction temperature had a great influence on the catalytic
activity. Regarding the type of structure, the total aromatics
selectivity in this work increased in the followed order for zeolites
modified with Zn: MCM-68 > TNU-15 > MCM-22. The medium pore zeolite
T9-15 (TNU-9 zeolite and Si/Al 15 ratio) catalysts with the ratio
ZnO/ZnO + Al2O3 equal to 0.34 (T9-15 0.5 Zn) showed better stability
with conversion of methanol completes during 9 h of reaction and 17% to
BTX selectivity and 32% to total aromatics compounds at 450 degrees C
and WHSV of 4.24 h(-1). In methanol conversion, the selectivity to
aromatics over the T9-15 modified-Zn materials (TNU-9 zeolite and Si/Al
15 ratio) under study, increased in the followed order: T9-15 0.5 Zn >
ZT9-15 > T9-15 > T9-15 0.2 Zn. The reaction temperature is an important
variable in the MTA process. At 450 degrees C a better activation of
acid sites is achieved in zeolite with Zn and therefore a high
percentage of BTX selectivity is obtained for TNU-9 zeolite.
Filiaciones:
Univ Autonoma Estado Mexico, Ciencia Mat, Fac Quim, Paseo Colon Esquina Paseo Tollocan S-N, Toluca 50000, Estado De Mexic, Mexico
Univ Autonoma Estado Mexico, Ctr Conjunto Invest Quim Sustentable, UNAM, Personal Acad Adscrito,Fac Quim, Toluca, Estado De Mexic, Mexico
UAM A, Area Quim Aplicada, Dept Ciencias Basicas, San Pablo 180, Cuidad De Mexico 02200, Mexico
CSIC, Inst Catalisis & Petroleoquim, C Marie Curie 2,Campus Cantoblanco, Madrid 28049, Spain
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