lubricant oils. Thus, the necessary prerequisites were created for processing the richest coal resources of Western Siberia, coal and natural gas from Ukhta and Pechora and other areas remote from the front into motor fuel. Nikolai Zelinsky died on July 31, 1953. He was buried in Moscow at the Novodevichy Cemetery (Division 1), and a headstone was made by Nilolai Nikoghosyan. Scientific activity Zelinsky's scientific activity was very versatile: his works on the chemistry of thiophene and the stereochemistry of organic dibasic acids are widely known. In the summer of 1891, Zelinsky participated in an expedition to survey the waters of the Black Sea and the Odessa estuaries on the gunboat Zaporozhets, where he proved for the first time that the hydrogen sulfide contained in the water was of bacterial origin. During the period of life and work in Odessa, Nikolai Zelinsky wrote 40 scientific papers. A number of his works were also devoted to electrical conductivity in non-aqueous solutions and to the chemistry of amino acids, but his main works were related to the chemistry of hydrocarbons and organic catalysis. In 1895-1907 he was the first to synthesize a number of cyclopentane and cyclohexane hydrocarbons, which served as standards for studying the chemical composition and the basis for artificial modeling of oil and oil fractions. In 1910 he discovered the phenomenon of dehydrogenation catalysis, which consists in the exclusively selective action of platinum and palladium on cyclohexane and aromatic hydrocarbons and in the ideal reversibility of hydro- and dehydrogenation reactions only depending on temperature. In 1911 he carried out a smooth dehydrogenation of cyclohexane and its homologues into aromatic hydrocarbons in the presence of platinum and palladium catalysts; he widely used this reaction to determine the content of cyclohexane hydrocarbons in gasoline and kerosene fractions of oil (1920-1930), and also as an industrial method for obtaining aromatic hydrocarbons from oil. These Zelinsky’s studies underlie the modern processes of catalytic reforming of petroleum fractions. Subsequent research led Zelinsky and his students to the discovery of the reaction of hydrogenolysis of cyclopentane hydrocarbons with their transformation into alkanes in the presence of platinized coal and excess hydrogen in 1934. In 1915, Zelinsky successfully used oxide catalysts for oil cracking, which led to a decrease in the process temperature and an increase in the yield of aromatic hydrocarbons. In 1918-1919, he developed a method for producing gasoline by solar oil and petroleum