DEEP HYDROGENATION OF 2-ETHYLANTHRAQUINONE OVER PD/SIO2 CATALYST IN THE LIQUID-PHASE

Hydrogenation of 2-ethylanthraquinone (eAQ) was carried out in a slurry reactor over Pd/SiO2 catalyst at atmospheric pressure of H-2 and room temperature. During hydrogenation 2-ethylanthrahydroquinone (eAQH2) was initially formed with a selectivity close to 100%. In the further process eAQH2 was hydrogenated and 2-ethyltetrahydroanthrahydroquinone (H4eAQH2) as the main product was formed in high yield (about 55-75%). eAQH-2 was also partly converted into other products termed 'degradation products'. The rate of hydrogenation, the yield of H4eAQH2 and the type of degradation products were examined as a function of the amount of catalyst. A complicated reaction pattern including consecutive (hydrogenation of aromatic rings) as well as parallel (hydrogenolysis of the carbon-oxygen bonds in eAQH-2) processes is postulated.