Friedel–Crafts alkylation of toluene with tert-butyl alcohol over Fe2O3-modified Hβ

RSC Advances ◽  
2016 ◽  
Vol 6 (109) ◽  
pp. 107239-107245 ◽  
Author(s):  
Yuanyuan Wang ◽  
Hua Song ◽  
Xinglong Sun
Keyword(s):  
Efficient Method ◽  
Strong Acid ◽  
Acid Sites ◽  
Butyl Alcohol ◽  
Tert Butyl ◽  
Highly Efficient ◽  
External Acid Sites ◽  
Tert Butyl Alcohol ◽  
Strong Acid Sites

Alkylation of toluene with TBA over Fe2O3 (x)/Hβ was studied. Modification by Fe2O3 is a highly efficient method for improving the para-selectivity by adjusting pore entrance and reducing the strong acid sites and external acid sites.

scholarly journals Enhancing Methane Conversion by Modification of Zn States in Co-Reaction of MTA

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1540
Author(s):  
Yue Yu ◽  
Zhixiang Xi ◽  
Bingjie Zhou ◽  
Binbo Jiang ◽  
Zuwei Liao ◽  
...  
Keyword(s):  
Active Site ◽  
Methane Conversion ◽  
Strong Acid ◽  
Acid Sites ◽  
Methane Activation ◽  
Reaction Conditions ◽  
Holy Grail ◽  
Highly Efficient ◽  
Strong Acid Sites ◽  
Capacity Loading

Limited by harsh reaction conditions, the activation and utilization of methane were regarded as holy grail reaction. Co-reaction with methanol, successfully realizing mild conversion below 450 °C, provides practical strategies for methane conversion on metal-loaded ZSM-5 zeolites, especially for highly efficient Zn loaded ones. However, Zn species, regarded as active acid sites on the zeolite, have not been sufficiently studied. In this paper, Zn-loaded ZSM-5 zeolite was prepared, and Zn was modified by capacity, loading strategy, and treating atmosphere. Apparent methane conversion achieves 15.3% for 1.0Zn/Z-H2 (16.8% as calculated net conversion) with a significantly reduced loading of 1.0 wt.% against deactivation, which is among the best within related zeolite materials. Besides, compared to the MTA reaction, the addition of methane promotes the high-valued aromatic production from 49.4% to 54.8%, and inhibits the C10+ production from 7.8% to 3.6%. Notably, Zn2+ is found to be another active site different from the reported ZnOH+. Medium strong acid sites are proved to be beneficial for methane activation. This work provides suggestions for the modification of the Zn active site, in order to prepare highly efficient catalysts for methane activation and BTX production in co-reaction with methanol.

scholarly journals Key Factors During the Milling Stage of the Seed Assisted and Solvent-Free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert-Butyl Alcohol

2021 ◽  
Author(s):  
Julieth García-Sánchez ◽  
Iván Darío Mora-Vergara Vergara ◽  
Daniel R. Molina V. ◽  
José Antonio Henao-Martínez ◽  
Víctor Gabriel Baldovino Medrano
Keyword(s):  
Physicochemical Properties ◽  
Milling Time ◽  
Acid Sites ◽  
Butyl Alcohol ◽  
The Other ◽  
Key Factors ◽  
Catalytic Behavior ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Input Variables

The so-called mechanochemical method for the synthesis of zeolites reduces the generation of liquid residues and gaseous pollutants as compared to the conventional solvothermal method. Different types of zeolites have been synthesized at the laboratory scale with this method using mostly pestle and mortar. However, such an approach hinders both the systematic comprehension of the effects of the input variables of the milling process and its further scale-up towards the synthesis of the zeolites and their catalytic application. This work investigates the influence of key factors involved in the ball milling stage of the mechanochemical route for the synthesis of MFI done with the assistance of a commercial MFI seed and in the absence of solvents over the most salient physicochemical properties of this type of materials, i.e. the recovery percentage, production cost, morphology, surface area and porosity, crystallinity, acidity of the protonated MFI and catalytic performance. The synthesis of the materials was planned and executed following a full 24 factorial experiment whose input variables were the Na2O/SiO2 and H2O/SiO2 molar ratios and the milling time and speed. The effects of both main and interaction factors over key physicochemical properties, and catalytic behavior of the synthesized materials on the alkylation of phenol with tert-butyl alcohol were established within the explored sampling space. Results showed that the Na2O/SiO2 molar ratio plays a key role for the mechanochemical synthesis of MFI, since this variable may direct the synthesis to the preferential production of MOR instead of MFI. On the other hand, it was found that the milling time and speed and their interactions markedly impact the textural properties of MFI. Furthermore, the triple interaction between the input variables affected the concentration of Lewis acid sites of the produced materials. These effects were rationalized by considering that sodium can act as a structure directing agent during the mechanochemical synthesis of MFI and also can promote the incorporation of aluminum to its structure. On the other hand, the milling time and speed are non-linearly correlated to the milling energy required for forming the aluminosilicate precursor that crystallizes during the hydrothermal stage of the process. Overall, all the zeolites synthesized by the mechanochemical route were less crystalline than both the MFI used as seed and an MFI synthesized by sol-gel. This was associated to the formation of amorphous agglomerates around the zeolitic crystals. Finally, the catalytic behavior of the mechanochemical MFI zeolites in the studied reaction was found to be linearly and positively correlated with both the concentration of BrØnsted of sites and with the density of acid sites. The catalytic tendencies were consistent with the proposal of a stepwise Langmuir-Hinshelwood mechanism for the alkylation of phenol with tert-butyl alcohol.

WOx/ZrO2: A highly efficient catalyst for alkylation of catechol with tert-butyl alcohol

2013 ◽  
Vol 378 ◽  
pp. 22-29 ◽  
Author(s):  
Arun Kumar ◽  
Asraf Ali ◽  
K.N. Vinod ◽  
Amit Kumar Mondal ◽  
Hemant Hegde ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Efficient Catalyst ◽  
Tert Butyl ◽  
Highly Efficient ◽  
Tert Butyl Alcohol

scholarly journals Key Factors During the Milling Stage of the Seed Assisted and Solvent-Free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert-Butyl Alcohol

2021 ◽  
Author(s):  
Julieth García-Sánchez ◽  
Iván Darío Mora-Vergara Vergara ◽  
Daniel R. Molina V. ◽  
José Antonio Henao-Martínez ◽  
Víctor Gabriel Baldovino Medrano
Keyword(s):  
Physicochemical Properties ◽  
Milling Time ◽  
Acid Sites ◽  
Butyl Alcohol ◽  
The Other ◽  
Key Factors ◽  
Catalytic Behavior ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Input Variables

The so-called mechanochemical method for the synthesis of zeolites reduces the generation of liquid residues and gaseous pollutants as compared to the conventional solvothermal method. Different types of zeolites have been synthesized at the laboratory scale with this method using mostly pestle and mortar. However, such an approach hinders both the systematic comprehension of the effects of the input variables of the milling process and its further scale-up towards the synthesis of the zeolites and their catalytic application. This work investigates the influence of key factors involved in the ball milling stage of the mechanochemical route for the synthesis of MFI done with the assistance of a commercial MFI seed and in the absence of solvents over the most salient physicochemical properties of this type of materials, i.e. the recovery percentage, production cost, morphology, surface area and porosity, crystallinity, acidity of the protonated MFI and catalytic performance. The synthesis of the materials was planned and executed following a full 24 factorial experiment whose input variables were the Na2O/SiO2 and H2O/SiO2 molar ratios and the milling time and speed. The effects of both main and interaction factors over key physicochemical properties, and catalytic behavior of the synthesized materials on the alkylation of phenol with tert-butyl alcohol were established within the explored sampling space. Results showed that the Na2O/SiO2 molar ratio plays a key role for the mechanochemical synthesis of MFI, since this variable may direct the synthesis to the preferential production of MOR instead of MFI. On the other hand, it was found that the milling time and speed and their interactions markedly impact the textural properties of MFI. Furthermore, the triple interaction between the input variables affected the concentration of Lewis acid sites of the produced materials. These effects were rationalized by considering that sodium can act as a structure directing agent during the mechanochemical synthesis of MFI and also can promote the incorporation of aluminum to its structure. On the other hand, the milling time and speed are non-linearly correlated to the milling energy required for forming the aluminosilicate precursor that crystallizes during the hydrothermal stage of the process. Overall, all the zeolites synthesized by the mechanochemical route were less crystalline than both the MFI used as seed and an MFI synthesized by sol-gel. This was associated to the formation of amorphous agglomerates around the zeolitic crystals. Finally, the catalytic behavior of the mechanochemical MFI zeolites in the studied reaction was found to be linearly and positively correlated with both the concentration of BrØnsted of sites and with the density of acid sites. The catalytic tendencies were consistent with the proposal of a stepwise Langmuir-Hinshelwood mechanism for the alkylation of phenol with tert-butyl alcohol.

Thermodynamic and Kinetic Investigation of the Solvent Effect on the Oxidation of [Co(en)2SCH2COO]+ with S2O82- In Water-Methanol and Water-tert-Butyl Alcohol Mixtures

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Transfer Functions ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Oxidation Of Co ◽  
Kinetics Of Oxidation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Alcohol Mixtures ◽  
Kinetics Of

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.

scholarly journals Impacts of Sn(II) doping on the Keggin heteropolyacid-catalyzed etherification of glycerol with tert-butyl alcohol

2021 ◽  
pp. 116913
Author(s):  
Márcio José da Silva ◽  
Diego Morais Chaves ◽  
Sukarno Olavo ferreira ◽  
Rene Chagas da Silva ◽  
Jose Balena Gabriel Filho ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Tert Butyl ◽  
Tert Butyl Alcohol
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