Degradation Reactions in Anthraquinone Process of Hydrogen Peroxide Synthesis

Abstract

Present research concentrates on the process of anthraquinone degradation in the course of hydrogenation carried out in the presence of palladium catalyst. Hydrogenation experiments were carried out using agitated glass laboratory batch type reactor at atmospheric pressure of hydrogen and temperature of 55 °C. Catalytic tests were performed using solutions composed of 2-ethyl-9,10-anthraquinone (eAQ) and a mixture of eAQ and 2-ethyloxanthrone (OXO) with various proportions. Degradation of anthraquinone was studied and in particular, the role of reduced forms of quinone namely hydroquinone and its tautomer OXO is discussed. A difference in the course of reactions pathways: hydrogenation of aromatic rings to give 2-ethyl-5,6,7,8-tetrahydro-9,10-anthraquinone (active quinone) and hydrogenolysis reactions yielding degradation products was observed. Present research concentrates on the process of 2-ethyl-9,10-anthraquinone degradation on palladium catalyst. The role of reduced forms, hydroquinone-enol form and its keto-tautomer is discussed.