Siberian Federal University

Vapor phase catalytic hydrogenation of dibutylketone (DBK) into n-nonane in the temperature range of 270-355 °C under a hydrogen pressure from 0.6 to 1.2 MPa was studied in the presence of 2 wt. % Pd/ZrO2 with different metal dispersions. It was found that DBK conversion and selectivity to n-nonane increase with an increase of temperature and a decrease in the size of the metal particles. The effect of water vapor and CO2 on the n-nonane yields was investigated in the whole temperature range. Reaction kinetics was explored and the reaction rate was found to be first order in DBK with an apparent activation energy of the reaction being estimated as 45.7 kJ/mol. The optimal reaction conditions of the hydrogenation reaction were elaborated providing the selectivity of 80 % towards n-nonane at full conversion of DBK. High activity and stability of Pd catalysts in the presence of water vapor and CO2 were observed. One-pot synthesis of n-nonane involving decarboxylative coupling of pentanoic acid followed by hydrogenation of the resulting DBK without its isolation was suggested to be realized over these catalysts. It was shown that Pd/ZrO2 catalyst demonstrated high stability during 9 hours of time-onstream