The systems suitable for a high‐temperature electrochemical synthesis on the surfaces of diamond, boron nitride, and silicon and boron carbides were selected on the basis of the thermodynamic analysis of the reactions of dielectrics and semiconductors with ionic melts and the study of their electrochemical behavior. Electroplating of the grains of dielectrics and semiconductors with molybdenum carbide favors the increase in their breaking load and wettability and in the efficiency of tools. Thermodynamic calculations showed that the most energy favorable process for boron nitride is its oxidation to gaseous nitrogen and boron metaborate or oxide. A compound of an element of group VI and carbon will be presumably reduced to this element in the pure state or to its oxide of an intermediate oxidation state. The most energy favorable process for silicon and boron carbides will be their oxidation to a metasilicate (metaborate) or silicon (boron) oxide. A compound of an element of group VI will be also presumably reduced to the elements in the pure state or in the form of an intermediate oxide.

Quantum-chemical calculations of the parameters of the nM+ ・ NbF7 q− type particles, where M stands for Na, K, Cs; q = 2,3 and n = 0 - 7 have been performed. Within the framework of this approximation, compositions for the most stable particles in molten salts were obtained. It is shown that electron transfer onto the particle results in a different redistribution of the electron density with the Na and K-particles on one hand and Cs-containing particles on the other hand. Energies and some other characteristics of the electron structure and particle geometry were determined depending on the n and M values.

Quantum-chemical calculations of the parameters of the nM+・NbClF2−6 type particles have been performed, where M stands for Na, K, Cs and n = 0 - 6. Under certain conditions such particles may exist in melts of alkali metal chlorides.Within the framework of this approximation, compositions for themost stable particles in molten salts were obtained. Relative stability of the particles containing the NbF−6 , NbClF2−6 , and NbF2−7 complexes has been calculated. Energies and some other characteristics of the electron structure and the particle geometry structure were determined depending on the n and M values. For estimation of the third sphere’s influence, the systems (M2NbF7 +8MCl) and (M2NbF7 +15MCl) are surveyed. The chlorine anion enters the first coordination sphere in the Nasystem only, i. e. in this system the true complex NbClF3−7 is formed.

It is shown that the cathode products of electrolysis of melts based on a eutectic mixture of sodium chloride and lithium fluoride as well as melts based on sodium tungstate in which dissolved oxides of molybdenum (VI) or tungsten (VI), molybdate, tungstate and lithium or sodium carbonates are molybdenum, tungsten, their bronzes and carbides, carbon. It is established that the phase composition of electrolysis products is determined by the concentration of carbonate in the melt. Particular conditions of plating coating of molybdenum and tungsten carbides on carbon, nickel and copper materials are determined. Molybdenum carbide coatings of electrolyte Na2WO4–Li2MoO4–Li2CO3 are deposited at equality (within 2.5 mol%) of concentrations molybdate and lithium carbonate. However, their concentrations should not exceed 10 mol%. At lower concentrations of molybdate in the precipitate are detected carbon, molybdenum, molybdenum carbide, and at high concentrations – molybdenum oxides. At lower concentrations of carbonate in the sediment dominates molybdenum and at large concentrations mainly free carbon is released. More affordable industrial reagent‐source of molybdenum is its oxide.

In the framework of the quantum-mechanical theory of elementary act of non-adiabatic electrochemical reactions, it is carried out the calculation of the discharge current of ions at the semiconductor-electrolyte solution interface using the model of isotropic spherically symmetric band. It is shown that our results generalize the well-known formulae for the current density obtained by Dogonadze, Kuznetsov, and Chizmadzhev [R. R. Dogonadze, A. M. Kuznetsov, and Yu. A. Chizmadzhev, The kinetics of some heterogeneous reactions at semiconductor-electrolyte interface, Zhur. Fiz. Khim. 38 (1964Khim. 38 ( ) 1195Khim. 38 ( -1202. The average densities of states in the valence band and the conduction band of the semiconductor electrode in the heterogeneous charge transfer are found.