2020 Roadmap on gas-involved photo-and electro-catalysis

In this roadmap, we address the development and perspectives of hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction.     

Theoretical Analysis of System’s Composition Changes in the Course of Electrolysis of Acidic Chloride Aqueous Solution

Russian Journal of Electrochemistry - Variations of the indicator electrode potential under zero current condition, E, and of the (quasi)equilibrium composition of the aqueous solution (which...     

Hydrogen-bromate flow battery: can one reach both high bromate utilization and specific power?

Journal of Solid State Electrochemistry - Hydrogen-bromate flow battery is a promising hybrid current source for air-deficient environment that functions by electrocatalyzed reactions of hydrogen...     

Experimental and theoretical study of the effect of the substituent nature on the luminescent properties of scandium complexes with substituted 8-hydroxyquinolines

The luminescent properties of homoleptic scandium complexes with 2-substituted 8-hydroquinolines bearing the substituent groups H (1), CH₃ (2), CN (3), and NH₂ (4) were studied for use as emission layers in organic light-emitting diodes. It was found that the introduction of a substituent into the 2-position makes its possible to effectively shift the emission maximum to the blue or red region: to 530 nm (yellow-green) by 1 and 2, 615 nm (orange) by 3, and 495 nm (blue-green) by 4. The structure and the optical properties of the complexes were determined by density-functional-theory quantum-chemical calculations. The theoretical spectra agree well with the experimental photoluminescence spectra.     

A Mixture of Phospho-, Vanadium-, and Molybdo-Heteropolyacids as a Promising Cathode Redox-Mediator for Hybrid Hydrogen–Air Fuel Cells

Russian Journal of Electrochemistry - Hydrogen–air fuel cell is one of the promising types of chemical power sources, it has a variety of applications. However, utilization of the cathodic...     

Copper electrodeposition into ion-exchange materials

Electrodeposition of copper into spherical granules of ion-exchange materials KU-23 and KU-2 out of acid sulfate solutions is studied by a method of cyclic voltammetry. It is discovered that the discharge of copper ions in an ion-exchange matrix is characterized by a cathodic overvoltage that is higher than the overvoltage of the same process on a graphite substrate by 0.08 V, which is most probably connected with a limited mobility of ions localized at fixed groups [RSO ₃ ^? ]. The cyclic voltammogram exhibits an additional cathodic peak in the potential region corresponding to the reduction of single-charged copper ions that form as a result of their accumulation inside pores of the ion-exchange matrix during anodic dissolution of metal deposited previously. It is fixed microscopically that the process of deposition begins at the graphite substrate/ion-exchanger interface and passes into bulk upon the formation of an electron-conducting layer saturated with copper. Preliminary saturation of the ion-exchanger by copper deposited chemically facilitates uniform electrodeposition of copper over the entire volume of pores of the ion-exchange matrix.     

General model selection estimation of a periodic regression with a Gaussian noise

This paper considers the problem of estimating a periodic function in a continuous time regression model with an additive stationary Gaussian noise having unknown correlation function. A general model selection procedure on the basis of arbitrary projective estimates, which does not need the knowledge of the noise correlation function, is proposed. A non-asymptotic upper bound for L₂{\mathcal{L}_2} -risk (oracle inequality) has been derived under mild conditions on the noise. For the Ornstein–Uhlenbeck noise the risk upper bound is shown to be uniform in the nuisance parameter. In the case of Gaussian white noise the constructed procedure has some advantages as compared with the procedure based on the least squares estimates (LSE). The asymptotic minimaxity of the estimates has been proved. The proposed model selection scheme is extended also to the estimation problem based on the discrete data applicably to the situation when high frequency sampling can not be provided.     

Development and Application of an Exponential Method for Integrating Stiff Systems Based on the Classical Runge–Kutta Method

We study numerical methods for solving stiff systems of ordinary differential equations. We propose an exponential computational algorithm which is constructed by using an exponential change of variables based on the classical Runge–Kutta method of the fourth order. Nonlinear problems are used to prove and demonstrate the fourth order of convergence of the new method.     

Spectroelectrochemical determination of the redox equivalent of magnesium porphine in the course of its electrooxidation

The spectroelectrochemical method has been applied for studying the electropolymerization of magnesium porphine with the aim to determine the number of electrons consumed per monomer molecule, which allows one to find out the number of bonds between the units in the resulting polymer. Based on the results, a conclusion has been made about the structure of macrochains of the basic representative of a new family of electroactive materials, magnesium porphine