German Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities

Operando XAS studies of direct synthesis of H2O2 over Pd catalysts

18 Sept 2018, 11:30

15m

MW 0350 (Fakultät für Maschinenwesen)

Talk MS4 Innovation and industry Micro symposium 4

Speaker

Dr Dmitry Doronkin (KIT)

Description

Hydrogen peroxide (H₂O₂) is a widely used powerful, environmentally benign oxidizing agent. The liquid phase catalyzed direct synthesis of H₂O₂ from molecular hydrogen and oxygen constitutes an attractive greener alternative to the industrial anthraquinone auto-oxidation process. However, insufficient mechanistic details hinder the development of enhanced catalysts and the choice of suitable reaction conditions for the direct synthesis of H₂O₂. Furthermore, safety concerns related to formation of explosive H₂/O₂ mixtures severely restrict in situ / operando studies of the direct synthesis of H₂O₂ as well as its commercial application. In order to gain insight in the catalytic processes occurring during the H₂O₂ synthesis at the molecular level, we performed operando XAS studies of Pd catalysts in a continuous flow reactor at pressures of 10-40 bar. Water and ethanol were used as solvents. In both cases H₂:O₂ ratio was varied while the complementary on-line product analysis allowed deriving structure-activity relationships and new insights into the mechanism of the direct H₂O₂ synthesis [1].

Reference
[1] M. Selinsek, B.J. Deschner, D.E. Doronkin, T.L. Sheppard, J.-D. Grunwaldt, R. Dittmeyer, ACS Catal. 8 (2018) 2546.