Thema der Dissertation:
Operando Investigation of Water Electro-Oxidation Kinetics in Bulk- Active Cobalt Oxyhydroxides
Operando Investigation of Water Electro-Oxidation Kinetics in Bulk- Active Cobalt Oxyhydroxides
Abstract: Hydrogen produced by electrochemical water splitting is considered a promising energy carrier for future sustainable energy systems. However, the oxygen evolution reaction (OER) at the anode is the major kinetic bottleneck due to its complex multi-electron transfer mechanism. In this study, cobalt-based oxyhydroxide electrocatalyst (CoCat) is employed as a model system for bulk-active catalysts for investigation of reaction kinetics. Electrochemical measurements combined with operando X-ray absorption spectroscopy (XAS), UV–Vis spectroscopy, and electrochemical impedance spectroscopy (EIS) reveal distinct timescales for double-layer charging, bulk redox transitions, and catalytic OER. Furthermore, temperature-dependent electrochemical measurements combined with operando XAS were performed to evaluate the activation energy parameters of the OER process and to investigate how the chemical state of the catalyst influences its catalytic activity. Overall, this work establishes a comprehensive mechanistic picture, linking redox charge accumulation to changes in the chemical state of the catalyst, and ultimately to its catalytic activity, thereby providing new insight into the fundamental origin of potential- and temperature-dependent OER activity in bulk-active transition-metal oxyhydroxides.
Time & Location
Sep 08, 2026 | 05:30 PM
Hörsaal A (1.3.14)
(Fachbereich Physik, Arnimallee 14, 14195 Berlin)