oxidation

Electrochemical Oxidation of VT6 Titanium Alloy in Oxalic Acid Solutions

The influence of the electrolysis parameters on the process of VT6 titanium alloy oxidizing in oxalic acid solutions is presented. It is shown that the nature of cell voltage-time curves for the alloy samples depends on the current density used. The interference-colored oxide films are formed on the surface of the alloy at the anodic current density above 0.5 A∙dm-2. The maximal thickness and the oxide film color are determined by the cell voltage and do not depend on other electrolysis parameters.

INFLUENCE OF HYDROPEROXIDE EPOXIDATION REACTION CONDITIONS OF OCTEN-1 ON THE PROCESS OF Mo2B ACTIVATION AND ON THE SELECTIVITY OF EPOXIDE FORMATION

A study of the process of activation of molybdenumboride catalyst in the reaction of epoxidation of octene-1 with tert-butyl hydroperoxide and the effect on this process of the initial concentration of octene-1, tert-butyl hydroperoxide and the amount of catalyst in the reaction mixture. As well as reaction products (tert-butyl alcohol and epoxy). It is shown that over time a new amorphous phase is formed on the surface of Mo2B, which actually catalyzes the epoxidation reaction of octene-1 with tert-butyl hydroperoxide.

CREATING THE BASIS OF NON-EXHAUSTIVE TECHNOLOGY OF CYCLOHEXAN OXIDATION

Cyclohexane oxidation is object of this research. One of the most problematic points of this process is low conversion of raw material and low selectivities for aim-products at conversions higher than 4%. One of the reasons for this is absence of modern effective catalytic systems that could increase mentioned indexes. One of the directions of solving these problems is the creation of a technology for the integrated use of the obtained oxidation products on the basis of the developed new effective catalytic systems, which will enable to increase the selectivity of the process.

Molecular Modelling of Acridine Oxidation by Peroxyacids

The optimal geometric structure and reactivity of some peroxyacids, acridine and products of their interaction were calculated by quantum-chemical methods. It was found that the heat of formation of peroxyacids (PA) and carboxylic acids (CA) grow with increasing length of a hydrocarbon radical. The dependencies of the area of PA and molecules of CA on the number of carbon atoms in the molecules are linear. The potentials of ionization of all studied PA are close and lie within the range of 11.22–11.39 eV depending on the calculation methods.

Kinetics of Os(VIII) Catalyzed Oxidation of 2-Pyrrolidine Carboxylic Acid in Alkaline Medium using Sodium Periodate as Oxidant: A Mechanistic Approach

The present paper deals with the kinetic and mechanistic investigation of Os(VIII) catalyzed oxidation of 2-pyrrolidinecarboxylic acid by sodium periodate (NaIO4) in alkaline medium in the temperature range of 303‒318 K. The experimental result shows a first order kinetics with respect to Os(VIII) and periodate while positive effect with respect to substrate i.e., 2-pyrrolidinecarboxylic acid was observed. The reaction showed negative effect for [OH-]. Negligible effect of Hg(OAc)2 and ionic strength of the medium was observed.

Low-Pressure Discharge Plasma Treatment of Aqueous Solutions with Mn, Cr and Fe

The effect of low-pressure glow discharge on the formation of peroxide and the degree of oxidation of Mn, Cr and Fe was studied in the aqueous solutions of different compounds. The plasma treatment causes the reduction of Mn(VII) through Mn(IV) to Mn(II), Cr(VI) to Cr(III) and oxidation of Fe(II) to Fe(III). Among other reactive species, peroxide formed under the action of plasma treatment takes an active part in redox reactions. The concentration of peroxide usually increases with treatment time, but its presence is detected only after completion of active redox processes.

Low Temperature Acrolein to Acrylic Acid Oxidation with Hydrogen Peroxide on Se-Organic Catalysts

Catalytic performance of Se-containing organic substances, namely methylseleninic acid, benzeneseleninic acid, phenylselenol and diphenyldiselenide, has been tested as potential catalysts for unsaturated aldehydes oxidation by hydrogen peroxide. All tested substances proved to be active in the acrolein oxidation reaction but showed different efficiency regarding used solvents and the products of reaction – acrylic acid or methyl acrylate. Optimal catalyst, reaction conditions and solvent for acrylic acid synthesis have been determined.

Research of the Process of Liquid Phase Selective Oxidation of 4-Aminotoluene with Ozone

According to the results of studying of kinetic relationships and mechanism of the process of catalytic oxidation of 4-aminotoluene with ozone in the liquid phase, the basis of the technology of 4-aminobenzyl alcohol and 4-aminobenzaldehyde have been developed. It has been shown that under the ozonation conditions in the solution of acetic anhydride in the presence of sulfuric acid, manganese(II) acetate or its mixture with potassium bromide it is possible to stop oxidation at the stage of forming 4-aminobenzyl alcohol or aldehyde.

About the correlation to activity of catalyst of Mо2B and selectivity of formation of epoxide in reaction of epoxidation oct-1-ene with tert-butyl hydroperoxide

This work is dedicated to the study of change of composition of surface of catalyst of Мо2В in the reaction of epoxidation of oct-1-ene tert-butyl hydroperoxide under the action of reactionary environment. And as with this process the constrained selectivity of formation of epoxide.

Presented results of x-ray phase analysis of initial and exhaust in a reaction epoxidation of standards of boride of molybdenum - Мо2В. The obtained data testify that both a weekend and exhaust catalyst contains one and that diffraction lances that answer one crystalline phase of Мо2В.