Complex iron catalytic systems: relative catalytic activity of various components

1994 ◽  
Vol 8 (1) ◽  
pp. 53-55 ◽  
Author(s):  
Malvina Farcasiu ◽  
Patricia A. Eldredge ◽  
Steven C. Petrosius
Keyword(s):  
Catalytic Activity ◽  
Catalytic Systems ◽  
Relative Catalytic Activity

Catalytic Activity of Binary and Triple Systems Based on Redox Inactive Metal Compound, LiSt and Additives of Monodentate Ligands-Modifiers: DMF, HMPA and PhOH, in Selective Ethylbenzene Oxidation with Dioxygen

2016 ◽  
Vol 10 (3) ◽  
pp. 259-270
Author(s):  
Ludmila Matienko ◽  
◽  
Larisa Mosolova ◽  
Vladimir Binyukov ◽  
Gennady Zaikov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Triple System ◽  
Metal Compound ◽  
Ethylbenzene Oxidation ◽  
Catalytic Systems ◽  
Triple Systems ◽  
Lithium Compound ◽  
Mechanism Of Catalysis ◽  
Monodentate Ligands

Mechanism of catalysis with binary and triple catalytic systems based on redox inactive metal (lithium) compound {LiSt+L2} and {LiSt+L2+PhOH} (L2=DMF or HMPA), in the selective ethylbenzene oxidation by dioxygen into -phenylethyl hydroperoxide is researched. The results are compared with catalysis by nickel-lithium triple system {NiII(acac)2+LiSt+PhOH} in selective ethylbenzene oxidation to PEH. The role of H-bonding in mechanism of catalysis is discussed. The possibility of the stable supramolecular nanostructures formation on the basis of triple systems, {LiSt+L2+PhOH}, due to intermolecular H-bonds, is researched with the AFM method.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Extreme Values ◽  
Catalytic Properties ◽  
Active Components ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Peroxide Decomposition ◽  
Two Component ◽  
Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

The relative catalytic activity of acids in hydrolytic caprolactam polymerization

1973 ◽  
Vol 5 (3) ◽  
pp. 339-340
Author(s):  
L. N. Mizerovskii ◽  
Yu. S. Paikachev ◽  
B. G. Silanteva ◽  
N. V. Sholichev
Keyword(s):  
Catalytic Activity ◽  
Caprolactam Polymerization ◽  
Relative Catalytic Activity

DECOMPOSITION OF SODIUM HYPOCHLORITE: THE CATALYZED REACTION

1956 ◽  
Vol 34 (4) ◽  
pp. 479-488 ◽  
Author(s):  
M. W. Lister
Keyword(s):  
Catalytic Activity ◽  
Sodium Hypochlorite ◽  
Small Extent ◽  
Copper Oxides ◽  
Iron Cobalt ◽  
First Order ◽  
Cobalt Nickel ◽  
Nickel Copper ◽  
Relative Catalytic Activity ◽  
Mechanism Of The Reaction

The catalyzed decomposition of sodium hypochlorite has been examined; the catalysts tried were manganese, iron, cobalt, nickel, and copper oxides. It was shown that in no case was the decomposition to chlorate and chloride accelerated, only the reaction to chloride and oxygen. Manganese and iron did not catalyze even the latter reaction, or only to a very small extent; this was in fairly concentrated sodium hypochlorite containing some sodium hydroxide. The manganese and iron are largely oxidized to permanganate and ferrate under these conditions. It was found that copper could catalyze the formation of permanganate and ferrate, and nickel the formation of permanganate. Cobalt catalyzed the reaction going to oxygen, and the rate was proportional to the cobalt added, but little dependent on the hypochlorite concentration; the same is true of nickel. Copper (as reported earlier) gives a catalyzed reaction not far from first order in hypochlorite. The activation energies were measured, and were consistent with the relative catalytic activity of these metals. The mechanism of the reaction is briefly discussed.

THE REGULARITIES OF THE ACTIVE SURFACE FORMATION OF TUNGSTATE-CONTAINING ZIRCONIA AS A CATALYST FOR C7-ALKANES ISOMERIZATION

2019 ◽  
Vol 62 (1-2) ◽  
pp. 73-88
Author(s):  
M.D. Smolikov ◽  
V.A. Shkurenok ◽  
S.S. Yablokova ◽  
D.I. Kir’yanov ◽  
A.S. Belyi
Keyword(s):  
Catalytic Activity ◽  
Synthesis Method ◽  
Active Surface ◽  
Oil Refining ◽  
Catalytic Systems ◽  
Acid Properties ◽  
Highly Active ◽  
Actual Direction ◽  
High Octane

The paraffin hydrocarbons isomerization is one of the most important processes in the oil refining industry, aimed at obtaining high-octane environmental components of modern gasolines. The actual direction in isomerization is the processing of the fraction, containing C7-alkanes. The review is devoted to modern concepts of the active rface formation of tungstate-containing zirconia, which is a highly active catalytic system for the isomerization of heptanes. The review deals with the influence of synthesis method of tungstate-containing zirconia, it’s chemical composition, phase structure and acid properties on the formation of the active surface of WO3/ZrO2 systems and their catalytic activity. The role of platinum in the catalytic systems WO3/ZrO2 for C7-alkanes isomerization is considered.

Synthesis of Esomeprazole through Asymmetric Oxidation

2014 ◽  
Vol 881-883 ◽  
pp. 351-355
Author(s):  
Zhi Cheng Li ◽  
Xiao Bo Kong ◽  
Wen Peng Mai ◽  
Gang Chun Sun ◽  
Shi Zhao Zhao
Keyword(s):  
Catalytic Activity ◽  
Cumene Hydroperoxide ◽  
Catalytic Systems ◽  
Asymmetric Oxidation ◽  
Good Catalytic Activity ◽  
Optimized Conditions

N,N'-dicyclohexyl-D-tartaric diamide 2a andN,N'-di-[(R)-inda-D-tartaric diamide 2b were prepared through the reaction of diethyl-D-tartrate with cyclohexylamine and (R)-(-)-1-aminoindan, respectively. The two compounds coordinated with isopropyl titanate (Ti (O-iPr)4), were used as catalyst in the asymmetric oxidation of pyrmetazol 3 with cumene hydroperoxide (CHP) as oxidant. The results revealed that both the catalytic systems derived from ligand 2a and 2b with Ti (O-iPr)4showed good catalytic activity and enantioselectivity in the synthesis of esomeprazole. Under the optimized conditions, the yield reached 91%, 91% and the enantio excess (ee) was up to 87% , 89%.

On the nature of active sites and catalytic activity for OCM reaction of alkaline-earth oxides-neodymia catalytic systems

2010 ◽  
Vol 375 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Florica Papa ◽  
Dana Gingasu ◽  
Luminita Patron ◽  
Akane Miyazaki ◽  
Ioan Balint
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Alkaline Earth ◽  
Catalytic Systems
Sign in / Sign up

Export Citation Format

Share Document