This article attempts to reveal, based on archival materials, the main directions of research activities of the outstanding scientist A. N. Frumkin (1895-1976) during His work at the L. ya.Karpov research Institute. It was at this time, from 1992 to 1946, that A. N. Frumkin worked his way up from the head of the Department of surface phenomena to the Deputy Director of the Institute for scientific work. The main directions of his research interests in the field of physical chemistry are shown. He paid special attention to the study of the surface properties of metals. In the circle of his interests included the study of adsorption phenomena. The "Frumkin isotherm" was developed, and the fundamental position about the zero charge potential was proved. A. N. Frumkin has repeatedly made scientific reports in leading scientific institutions in Germany, the USA, the Netherlands, and others. A. N. Frumkin's contribution to the development of electrochemistry, which is of great importance for both science and practice, was appreciated. His scientific work was highly appreciated by the government. Thus, it was during the "Karpov period" of A. N. Frumkin's scientific activity that the most important fundamental research was carried out, which for many years determined the directions of development of physical and chemical science, and an authoritative scientific school of electrochemistry was formed.