scholarly journals Integrated Study of the Thiocyanate Anion Electrooxidation by Electroanalytical and Computational Methods

Author(s):  
Andrey Mendkovich ◽  
Yuriy Kozyrev ◽  
Vladimir Kokorekin ◽  
Victor Luzhkov ◽  
Alexander Rusakov

Abstract The mechanism of the electrochemical oxidation of thiocyanate anion in acetonitrile was studied by cyclic voltammetry, chronoamperometry, electrolysis, digital simulations and quantum chemical calculations. The experimental data indicated the complex character of the reaction mechanism, which includes reactions of thiocyanate anion with the products of its oxidation, thiocyanate radical and thiocyanogen. It was proposed that the last reaction takes place in the reduction of thiocyanogen as well. The DFT PCM-SMD M06–2X/aug-cc-pVQZ calculations show that the reaction of thiocyanate anion with thiocyanate radical • and disproportionation of thiocyanogen anion radical are thermodynamically favorable. The effects of the mentioned reactions on the shape of the curves of cyclic voltammetry and chronoamperometry as well as that of the mass transfer regime are discussed.

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Andrey S. Mendkovich ◽  
Mikhail A. Syroeshkin ◽  
Ludmila V. Mikhalchenko ◽  
Mikhail N. Mikhailov ◽  
Alexander I. Rusakov ◽  
...  

Electroreduction of 1,2-, 1,3-, and 1,4-dinitrobenzenes in DMF has been investigated by a set of experimental (cyclic voltammetry, chronoamperometry, and controlled potential electrolysis) and theoretical methods (digital simulation and quantum chemical calculations). The transformation of only one nitro group is observed in the presence of proton donors. The process selectivity is provided by reactions of radical anions' intermediate products. The key reactions here are protonation of radical anions of nitrosonitrobenzenes and N-O bond cleavage in radical anions of N-(nitrophenyl)-hydroxylamines.


1982 ◽  
Vol 47 (7) ◽  
pp. 1911-1922 ◽  
Author(s):  
Jiří Sedláček

CNDO/2 calculations have been made for simple models od adsorption of chloroalkane, alcohol, amine and thiol molecules on the surface of polar catalysts. The calculated values of selected quantum chemical quantities describing the properties of Cα-X and Cβ-HA bonds were correlated with reported experimental reactivities. Very good correlations with experimental data were obtained for quantum chemical quantities relating to the Cα-X bond. The results of calculations are discussed in relation to the reaction mechanism and the type of surface catalytic centres participating in the reaction.


1982 ◽  
Vol 47 (3) ◽  
pp. 766-775 ◽  
Author(s):  
Václav Kolář ◽  
Jan Červenka

The paper presents results obtained by processing a series of published experimental data on heat and mass transfer during evaporation of pure liquids from the free board of a liquid film into the turbulent gas phone. The data has been processed on the basis of the earlier theory of mechanism of heat and mass transfer. In spite of the fact that this process exhibits a strong Stefan's flow, the results indicate that with a proper definition of the driving forces the agreement between theory and experiment is very good.


1985 ◽  
Vol 50 (4) ◽  
pp. 920-929 ◽  
Author(s):  
Jiří Sedláček

CNDO/2 calculations for simple models of adsorption and dehydration reactions of secondary aliphatic and aromatic alcohols on polar catalysts are presented. The models involve selected stages of elimination mechanisms of various types (E1, E2 and E1cB elimination). Calculated quantum chemical quantities were correlated with reported experimental data. It is shown that reactivities for the series of substituted phenylethanols correlate very well with the ease of carbonium ion formation. In the case of aliphatic alcohols, calculated quantities correlate generally with the reactivities on SiO2 and are in anticorrelation with the reactivities on Al2O3.NaOH.


1993 ◽  
Vol 58 (5) ◽  
pp. 1078-1086
Author(s):  
Zdeněk Palatý

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.


2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.


2010 ◽  
Vol 24 (18) ◽  
pp. 1963-1970 ◽  
Author(s):  
ARVIDS STASHANS ◽  
RICHARD RIVERA

Structural and optical properties of F-center (two electrons trapped by an oxygen vacancy) defect in hematite have been studied using a quantum-chemical model. Calculated absorption energies, 0.9 eV and 3.6 eV, are discussed in terms of the available experimental data. An explanation for the origin of experimentally observed electron depletion in hematite is proposed.


Synthesis ◽  
2021 ◽  
Author(s):  
Alexander Schepochkin ◽  
Oleg N. Chupakhin ◽  
Nadezhda Demina ◽  
Maxim Averkov ◽  
Tatyana Shimanovskaya ◽  
...  

The effect of chalcogenophosphoryl fragments on the anodic oxidation of 9-chalcogenophosphoryl-9,10-dihydroacridines was studied in detail. The data of X-ray structural analysis, quantum chemical calculations and cyclic voltammetry obtained for these compounds provide an explanation of the observed features. The direct electrochemical phosphorylation of acridine was first carried out successfully.


2021 ◽  
Vol 1038 ◽  
pp. 108-115
Author(s):  
Yuliana Hapon ◽  
Maksym Kustov ◽  
Volodumur Kalugin ◽  
Alexander Savchenko

The paper deals with experimental data regarding the effect of internal and external factors on the corrosion decay of Zr1Nb alloy fuel elements. Based on the analysis results, losses of zirconium that transfers to oxide or coolant as per the fuel element wall weight and thickness as well as economic losses from their corrosion decay have been theoretically calculated. To avoid a state-level emergency occurrence, an increase in the fuel element wall thickness up to 660 μm is proposed, which can increase the operating life under the conditions of trouble-free coolant mass transfer hydrodynamic mode.


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