Catalytic properties of calcium-neodymium type Y zeolites in toluene disproportionation reaction

1975 ◽  
Vol 24 (1) ◽  
pp. 98-103
Author(s):  
Ya. I. Isakov ◽  
Kh. M. Minachev ◽  
N. Ya. Usachev
Keyword(s):  
Catalytic Properties ◽  
Disproportionation Reaction ◽  
Y Zeolites ◽  
Toluene Disproportionation

Catalytic Properties of Fluorine Modified SmNa-Y Zeolites

1992 ◽  
Vol 57 (4) ◽  
pp. 781-787 ◽  
Author(s):  
Stanisłav Kowalak ◽  
Maria Pawłowska ◽  
Kenneth J. Balkus
Keyword(s):  
Catalytic Properties ◽  
Acid Sites ◽  
Y Zeolites ◽  
Cumene Cracking ◽  
Toluene Disproportionation ◽  
Zeolite Nay ◽  
Polyvalent Cations ◽  
Protonic Acid ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

It is known that mild fluorination of zeolites, including those modified with polyvalent cations, increases their activity for acid catalyzed reactions. In this study we report the reactivity of fluorine modified Sm(III) exchanged zeolite NaY. Mild fluorination of SmNaY reduces the activity of strong protonic acid sites and increases the contribution of weak aprotic acid centres. Results for cumene cracking and toluene disproportionation as well as for 1-hexene isomerization are reported.

Aromatic Transformation in Fluidized Bed Reactors

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1061-1088
Author(s):  
Sule Rabiu ◽  
Sulaiman Al-Khattaf
Keyword(s):  
Fluidized Bed ◽  
The Other ◽  
Fluidized Bed Reactors ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Toluene Disproportionation ◽  
Xylene Isomerization ◽  
Toluene Methylation ◽  
Toluene Conversion ◽  
Medium Acidity

In this work three important aromatic transformations, namely: toluene disproportionation, toluene methylation and m-xylene isomerization, were investigated in a riser simulator which closely mimics the operation of commercial fluidized bed reactors. The transformations were studied over a ZSM-5 based catalyst with medium acidity of 0.23 mmol/g and a series of Y zeolites of acidities between 0.55 and 0.03 mmol/g. For pure toluene feed, it was observed that conversion over the ZSM-5 based catalyst and the weakly acidic Y zeolite (USY-1) was very low. However, with the highly acidic Y zeolite (H-Y), significant toluene conversion was observed with paring reaction more prominent than disproportionation. On the other hand, when toluene was alkylated with methanol, higher toluene conversions were achieved over both the ZSM-5 based and the weakly acidic USY-1 catalysts as compared to when pure toluene feed was used. In addition, p-xylene/o-xylene (P/O) ratios higher than the equilibrium values were obtained in the reaction product over both catalysts. Finally, for m-xylene isomerization it was found that m-xylene conversion increased initially as the acidity of the catalyst increased up to 0.1 mmol/g beyond which any further increase in acidity resulted in a slight decrease in the m-xylene conversion.

Insight into tri-coordinated aluminum dependent catalytic properties of dealuminated Y zeolites in oxidative desulfurization

2021 ◽  
Vol 288 ◽  
pp. 120022
Author(s):  
Zhiguo Zhu ◽  
Haikuo Ma ◽  
Weiping Liao ◽  
Pengpeng Tang ◽  
Kaixuan Yang ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Oxidative Desulfurization ◽  
Y Zeolites ◽  
Insight Into

Structural and Catalytic Properties of the Alkali Metal Ion-Exchanged Y-Zeolites by 29Si and 27Al Solid-State NMR and FT-IR Spectroscopy

2005 ◽  
Vol 277-279 ◽  
pp. 708-719
Author(s):  
Chang Seop Lee ◽  
Hee Jung Lee ◽  
Sung Woo Choi ◽  
Jahun Kwak ◽  
Charles H.F. Peden
Keyword(s):  
Solid State ◽  
Alkali Metal ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Nmr Spectra ◽  
Catalytic Properties ◽  
Nox Reduction ◽  
29Si Nmr ◽  
Y Zeolites ◽  
X Ray

A series of cation exchanged Y-zeolites were prepared by exchanging cations with various alkali (M+, M= Li, Na, K, Cs) metals. The structural and catalytic properties of the alkali metal exchanged Y-zeolites have been investigated by a number of analytical techniques. Comparative elemental analyses were determined by an Energy Dispersive Spectroscopy X-ray (EDS), X-ray Photoelectron Spectroscopy (XPS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) and X-ray Fluorescence (XRF) before and after cation substitution. The framework and non-framework Al coordination and the Si/Al ratios of the Y-zeolites were investigated by MAS Solid-State Nuclear Magnetic Resonance (NMR) spectroscopy. The Al NMR spectra were characterized by two 27Al resonance signals at 12 and 59 ppm, indicating the presence of the non-framework and framework Al respectively. The intensities of these resonances were used to monitor the amount of the framework and non-framework Al species in the series of exchanged zeolites. The 29Si NMR spectra were characterized by four resonance signals at -79, -84, -90, and -95 ppm. Changing the alkali metal cations in the exchanged Y-zeolites significantly altered the extent of the octahedral/tetrahedral coordination and the Si/Al ratio. The Fourier Transform Infrared spectra of the CO2 adsorbed on to the exchanged Y-zeolites showed a low frequency shift, as the atomic number of the exchanged alkali metal increased. In addition, the catalytic activity of these samples for NOx reduction were tested in combination with a non-thermal plasma technique and interpreted based on the above structural and spectroscopic information.

Kinetics and optimization of the toluene disproportionation reaction over solid acid catalysts

1987 ◽  
Vol 33 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Jen-Ray Chang ◽  
Fong-Chang Sheu ◽  
Ying-Ming Cheng ◽  
Jung-Chung Wu
Keyword(s):  
Solid Acid ◽  
Disproportionation Reaction ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Toluene Disproportionation
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