TP3: Operando characterization of catalysts during H2O2 synthesis
Dr. Dmitry Doronkin
Dr. Paolo Ciocci
Ananya Mohanty
Motivation and objectives:
The aim of this project is the spectroscopic investigation of defined model catalysts (mainly supported Pt-Au and Pd-Au) in their as-prepared state, during the reaction in the direct hydro-gen peroxide synthesis from H2 and O2 (t-HP) and the electrochemical H2O2 synthesis (e-HP) as well as under relevant in situ conditions and after t-HP and e-HP. To elucidate the catalyst structure during the reaction, we will apply operando characterization tools, in particu-lar X-ray absorption spectroscopy (XAS), but also infrared (IR) spectroscopy. This will allow us to uncover the influence of reaction conditions on the catalyst structure and unravel dy-namic processes such as alloying / segregation, oxidation / reduction, and adsorption / de-sorption of reactants, intermediates, and products as reaction conditions change. By combin-ing the XAS with complementary IR spectroscopy, we aim to correlate reaction conditions (partial pressures, pH, potential, solvents, halide / acid promoters etc.) with catalyst perfor-mance and structure. As a result, catalytically active site motifs and surface species will be determined which will serve as feedback for catalyst preparation and input for microkinetic modeling of t-HP and e-HP.