The turnover frequencies of catalytic systems based on DD 3/4 (acac)(2)-AlEt3 or AlEt2(OEt) in the hydrogenation of benzene have been determined at temperatures of 80-150 A degrees D, initial D (De2) = 15 bar, and Al/DD 3/4 ratios = 1-8. It has been shown that the benzene hydrogenation rate is directly proportional to the DD 3/4 (acac)(2) concentration and hydrogen pressure, while it does not depend on the concentration of benzene at D-D6De6 > 1 x 10(-2) mol/L. The parameters of the Arrhenius equation in the hydrogenation of benzene for the systems based on DD 3/4 (D degrees ND degrees N)(2)-AlEt3/AlEt2(OEt) were determined. It has been found that nanosized particles containing cobalt in the zero oxidation state exhibit catalytic activity in the benzene hydrogenation. [GRAPHICS] .