Studies on the oxidation of 2,6-di-tert-butylphenol by molecular oxygen catalyzed by cobalt(II) tetraarylporphyrins bound to cationic latex

2005 ◽  
Vol 09 (09) ◽  
pp. 621-625 ◽  
Author(s):  
Mahmoud T. Hassanein ◽  
Shady S. Gerges ◽  
Mohamed A. Abdo ◽  
Sahar H. El-Khalafy
Keyword(s):  
Catalytic Activity ◽  
Oxidative Coupling ◽  
Ammonium Ion ◽  
Reaction Products ◽  
Constant Concentration ◽  
Emulsion Copolymerization ◽  
Tert Butyl ◽  
Good Catalytic Activity ◽  
Autoxidation Reaction ◽  
Cationic Latex

A cationic latex has been prepared by emulsion copolymerization of styrene and divinylbenzene with 2 mol.% of quaternary ammonium ion surfactant monomer. The catalytic activity of cobalt(II) sulfonated tetraarylporphrins 1-5 supported on the cationic latex 6 was investigated in the autoxidation of 2,6-di-tert-butylphenol in water. All colloidal catalysts showed good catalytic activity in the autoxidation of 2,6-di-tert-butylphenol. Reaction products were identified as 2,6-di-tert-butyl-1,4-benzoquinone and the oxidative coupling product as 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone. The rate of autoxidation reaction catalyzed by 5 supported on cationic latex was found to increase with increasing pH in the range 7.0-10.0. At constant concentration of cobalt(II) porphyrin 5 in the reaction mixture, the rate as a function of the weight of the latex showed a maximum. The rate of autoxidation increased with increasing partial pressure of dioxygen in the range between 0.2 and 1.0 atm. 5,10,15,20-tetrakis(2,4,6-trimethyl-3,5-disulfonatopheny)porphyrinatocobalt(II) bound to the cationic latex was found to be the most reactive catalyst and the latex supported 5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphyrinatocobalt(II) showed the highest stability.

scholarly journals Crystal structure and catalytic activity of tetrakis(μ2-ethyl 2,6-di-tert-butyl-4-methylphenyl phosphato-κ2 O:O′)bis(ethyl 2,6-di-tert-butyl-4-methylphenyl phosphato-κ2 O,O′)dilutetium n-heptane disolvate

2018 ◽  
Vol 74 (4) ◽  
pp. 543-547 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Alexander N. Tavtorkin ◽  
Sof'ya A. Korchagina ◽  
Ilya E. Nifant'ev ◽  
Andrei V. Churakov
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
Title Complex ◽  
Polymerization Process ◽  
Vacuum Drying ◽  
Coordination Modes ◽  
Tert Butyl ◽  
Mild Conditions ◽  
Good Catalytic Activity ◽  
Ethyl Phosphate

The title complex, [Lu2(C17H28O4P)6]·2C7H16, was formed in the reaction between potassium 2,6-di-tert-butyl-4-methylphenyl ethyl phosphate, [K(2,6- t Bu2-4-MeC6H2-O)(EtO)PO2], and LuCl3(H2O)6 in water, followed by vacuum drying and recrystallization from heptane. Its crystal structure has triclinic (P-1) symmetry at 120 K. The lutetium tris(phosphate) complex has a binuclear [Lu2(μ-OPO)4] core and the organophosphate ligand exhibits κ2 O,O′ terminal and μ2-κ1 O:κ1 O′ bridging coordination modes with the LuIII ion being sixfold coordinated. The complex is of interest as a precatalyst in the acrylonitrile polymerization process and displays good catalytic activity under mild conditions.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

scholarly journals CO Oxidation Efficiency and Hysteresis Behavior over Mesoporous Pd/SiO2 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131 ◽  
Author(s):  
Rola Mohammad Al Soubaihi ◽  
Khaled Mohammad Saoud ◽  
Myo Tay Zar Myint ◽  
Mats A. Göthelid ◽  
Joydeep Dutta
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Active Sites ◽  
Bond Activation ◽  
Dissociative Adsorption ◽  
High Catalytic Activity ◽  
Good Catalytic Activity ◽  
Pretreatment Conditions ◽  
Oxidation Efficiency

Carbon monoxide (CO) oxidation is considered an important reaction in heterogeneous industrial catalysis and has been extensively studied. Pd supported on SiO2 aerogel catalysts exhibit good catalytic activity toward this reaction owing to their CO bond activation capability and thermal stability. Pd/SiO2 catalysts were investigated using carbon monoxide (CO) oxidation as a model reaction. The catalyst becomes active, and the conversion increases after the temperature reaches the ignition temperature (Tig). A normal hysteresis in carbon monoxide (CO) oxidation has been observed, where the catalysts continue to exhibit high catalytic activity (CO conversion remains at 100%) during the extinction even at temperatures lower than Tig. The catalyst was characterized using BET, TEM, XPS, TGA-DSC, and FTIR. In this work, the influence of pretreatment conditions and stability of the active sites on the catalytic activity and hysteresis is presented. The CO oxidation on the Pd/SiO2 catalyst has been attributed to the dissociative adsorption of molecular oxygen and the activation of the C-O bond, followed by diffusion of adsorbates at Tig to form CO2. Whereas, the hysteresis has been explained by the enhanced stability of the active site caused by thermal effects, pretreatment conditions, Pd-SiO2 support interaction, and PdO formation and decomposition.

A Three Component Iodine-Catalyzed Oxidative Coupling Reaction: A Heterodifunction of 3-Methylindole

2021 ◽  
Author(s):  
Wei Zhang ◽  
Shiqun Xiang ◽  
Weibin Fan ◽  
Jiang Jin ◽  
Yinghua Li ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Coupling Reaction ◽  
Peroxy Radicals ◽  
Metal Free ◽  
Tert Butyl ◽  
Oxidative Coupling Reaction

A metal-free synthesis of heterodifunctional indole derivaties is developed through TBHP/KI-mediated oxidative coupling. The reaction constructs C-O and C-C bonds in succession with the help of tert-butyl peroxy radicals generated...

scholarly journals Palladium-Supported Zirconia-Based Catalytic Degradation of Rhodamine-B Dye from Wastewater

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1522
Author(s):  
Salma Jabeen ◽  
Muhammad Sufaid Khan ◽  
Rozina Khattak ◽  
Ivar Zekker ◽  
Juris Burlakovs ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rhodamine B ◽  
Dye Degradation ◽  
Freundlich Isotherm ◽  
Impregnation Method ◽  
K Value ◽  
First Order Kinetics ◽  
Good Catalytic Activity ◽  
Rhodamine B Dye ◽  
Best Fit

The catalytic activity of Pd/ZrO2 was studied in terms of the degradation of rhodamine-B dye in the presence of hydrogen peroxide. Pd/ZrO2 was prepared by impregnation method, calcined at 750 °C and characterized by XRD, SEM and EDX. The catalyst showed good catalytic activity for dye degradation at 333 K, using 0.05 g of the catalyst during 5 h. The reaction kinetics followed the pseudo-first order kinetics. The Freundlich, Langmuir and Temkin isotherms were applied to the data and the best fit was obtained with Freundlich isotherm. Thermodynamic parameters, like ΔH, ΔG and ΔS were also calculated. The negative values of ΔH (−291.406 KJ/mol) and Gibbs free energy (ΔG) showed the exothermic and spontaneous nature of the process. The positive ΔS (0.04832 KJ/mol K) value showed suitable affinity of catalyst for dye degradation. The catalyst was very stable, active and was easily separated from the reaction mixture by filtration. It can be concluded from the results that the prepared catalyst could be effectively used in dyes degradation/removal from water subjected to further validation and use for various dyes.

What factors influence the catalytic activity of iron–salan complexes for aerobic oxidative coupling of 2-naphthols?

2012 ◽  
Vol 48 (47) ◽  
pp. 5823 ◽  
Author(s):  
Kenji Matsumoto ◽  
Hiromichi Egami ◽  
Takuya Oguma ◽  
Tsutomu Katsuki
Keyword(s):  
Catalytic Activity ◽  
Oxidative Coupling

scholarly journals Transformation of 2-Butene into Propene on WO3/MCM-48: Metathesis and Isomerization of n-Butene

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 585 ◽  
Author(s):  
Derun Hua ◽  
Zheng Zhou ◽  
Qianqian Hua ◽  
Jian Li ◽  
Xinning Lu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Temperatures ◽  
Thermodynamic Analysis ◽  
Reaction Temperature ◽  
Thermodynamic Calculations ◽  
Metathesis Reaction ◽  
Good Catalytic Activity

The metathesis of 2-butene (Trans and Cis) to propene was investigated over W-based catalysts. Thermodynamic calculations for metathesis and isomerization were carried out at various temperatures to test the reactions. The results showed that the WO3/MCM-48 catalyst had good catalytic activity. The metathesis activity depended on the acidity of the catalyst and the dispersity of the WO3 on the supports. High temperatures promoted the isomerization of 2-butene to 1-butene. According to thermodynamic analysis, however, this is adverse to the metathesis reaction, making it important to determine an appropriate reaction temperature.

Synthesis, Characterization, and Crystal Structure of Several Novel Acidic Ionic Liquids: 1-ethyl-2-alkyl-benzimidazolium Tetra-Fluoroborate

2013 ◽  
Vol 457-458 ◽  
pp. 139-143 ◽  
Author(s):  
Ming Tian Wang ◽  
Chang Ping Pan ◽  
Wei Peng Gai ◽  
Xiao Xia Lv ◽  
Min Gang Zhai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ionic Liquid ◽  
Acetic Acid ◽  
Catalytic Activity ◽  
Lamellar Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acidic Ionic Liquid ◽  
Acidic Ionic Liquids ◽  
Good Catalytic Activity

A series of novel acidic ionic liquid: 1-ethyl-2-alkyl-benzimidazolium tetra-fluoroborate (alkyl= Et, Pr-n, Bu-n) were prepared by simple acid-based neutralization of 1-ethyl-2-alkyl-benzimidazole and tetrafluoroboric acid. The compounds were characterized by FTIR spectra, elemental analysis,1HNMR spectra and thermogravimetric analysis. These novel tetra-fluoroborate salts show good catalytic activity to esterification of benzyl alcohol and acetic acid. Furthermore, a crystal of ([H-ebBiBF4) was prepared with the crystal structure and determined by X-ray diffraction analysis. The molecular is of lamellar structure as mainly π electron ring is stacked interleaving between two layers. The results of cation and anion arranged orderly in pair indicate that the coulombic attraction is more dominant. Simultaneously, the weak local hydrogen bonds C-H···F exist in the molecules.

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