Hydrogenation of 2-ethylanthraquinone over Pd/poly(4-vinylpyridyne) catalysts

Polymer, namely poly(4-vinylpyridyne) (PVP) was used as a support for palladium catalysts acting in liquid phase hydrogenation of 2-ethylanthraquinone (eAQ), a key step in industrial production of hydrogen peroxide. The catalytic hydrogenation was carried out in a slurry reactor at atmospheric pressure of H-2 and temperature 43 degreesC. The progress of eAQ hydrogenation over Pd/PVP catalyst was the same as observed earlier in the presence of Pd/SiO2. In initial stage of reaction eAQ was reduced with high selectivity to eAQH(2) (2-ethylanthrahydroquinone). In the further process termed "deep hydrogenation" hydrogenation of aromatic rings (formation of tetrahydroanthrahydroquinone H(4)eAQH(2)) and hydrogenolysis of carbon-oxygen bonds (formation of degradation products) in eAQH(2) proceeded. It was stated that in the presence of mass transport limitations the progress of reactions leading to the formation of "degradation products" was intensive.