RELATİONSHİP BETWEEN ELECTRICAL AND CATALYTIC IN THE REACTION OF CONVERSION OF ETHANOL TO ACETONE

Abstract

Low molecular weight ketones are among the most important products widely used in industry, however, the existing methods for their production are multistage. The significant disadvantages of these methods include the implementation of individual stages at high temperatures and pressures. As a result, the development of more economical and easy-to-implement processes is presented as an actual task for the basic organic synthesis industry. Recently, ethanol has been considered as a possible feedstock for the production of acetone. The prospect of using ethanol as a feedstock is due to the large renewable resources for its production. The growing interest in recent years in the production of ethanol by processing agricultural products and waste from the food and woodworking industries will undoubtedly stimulate further development of the method of producing acetone from ethanol. The catalytic conversion of ethanol to acetone is a relatively new method for producing acetone and, naturally, the number of publications devoted to this process is relatively small. In previously published works, as a rule, the issues of the mechanism of the process, as well as the relationship between the physicochemical and catalytic properties of the proposed active systems in these reactions, are not considered in detail. Active and selective catalysts were selected for the conversion reaction of ethanol to acetone, the mechanism of the process and the relationship between the physicochemical and catalytic properties of the activated sample were studied. The experiments were carried out on an active catalyst with the composition ZnO:CaO=9:1 The main provisions of the electronic theory of catalysis are developed in application to semi¬con-ductors, since, firstly, the theory of semiconductors is now more developed, and secondly, most of the catalysts used in practice belong to semiconductors. The surface of a semiconductor is the protection of two phases: a solid body-gas. The approach to this boundary from the side of the gaseous environment is essential for catalysis. The environment affects the surface and volume of the solid body. The influence of the environment is carried out through adsorption, as a result, the Fermi level shifts, and the electrophysical pro¬pert¬ies of catalysts change in the processes of adsorption and catalysis. Reactions of heterogeneous-catalytic transformation of low molecular weight alcohols are of great practical importance. The relevance of catalytic transformations of ethanol into various valuable products is the most important task of modern catalytic chemistry. To elucidate the mechanism of these reactions, a necessary step is to study the nature of the electronic interaction of reactants with a solid body, since the vast majority of catalysts of heterogeneous-catalytic oxidation - metal oxides, semiconductors, so especially promising is to involve methods for studying the electro physical properties of the surface. Changing these properties and studying the nature of their change in the atmosphere of the reactants, it is possible obtain valuable information about the nature of the electronic interaction of the reactant-catalyst. The works carried out in this direction showed that in most cases the process of chemisorption is accompanied by the appearance of an additional surface potential, indicating the charging of the surface in the presence of a particular reactant. The electrical and catalytic properties of a series of active zinc-calcium oxide catalysts were studied (their activity was also studied in previous experiments). The study of the electrical properties of the catalyst is of the greatest interest for elucidating the mechanism of reactions, since they can provide information about the nature of electronic transitions that limit the course of the reaction. The number of different factors determines the catalytic activity of a solid body. Each of these factors can correlate with certain properties of a solid body. When comparing catalytic and electrophysical properties electrical conductivity is most often measured. Measuring on the same catalyst sample under the same conditions of conductivity change can provide useful information about mechanism of action of the catalyst and the course of the catalytic reaction. Studies of the electrical conductivity of the synthesized catalysts have shown that all the catalysts studied are semiconductors. This article shows the relationship between the electrical and catalytic properties of zinc-calcium oxide catalysts. Keywords: catalyst, electrical conductivity, activation energy, adsorption, ethanol, acetone.