| AVS 63rd International Symposium & Exhibition | |
| In-Situ and Operando Spectroscopy and Microscopy for Catalysts, Surfaces, & Materials Focus Topic | Wednesday Sessions |
| Session IS+HC-WeA |
| Session: | Ambient Pressure XPS Studies of Surface and Chemistry of Catalysts |
| Presenter: | Axel Knop-Gericke, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany |
| Authors: | V. Pfeifer, Fritz-Haber-Institut der Max-Planck-Gesellschaft and Helmholtz-Zentrum Berlin, Germany J.J. Velasco-Velez, Max-Planck-Institut für Chemische Energiekonversion, Germany R. Arrigo, Diamond Light Source Ltd., UK T.E. Jones, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany M. Hävecker, Max-Planck-Institut für Chemische Energiekonversion, Germany E. Stotz, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany R. Schlögl, Fritz-Haber-Institut der Max-Planck-Gesellschaft and Max-Planck-Institut für chemische Energiekonversion, Germany A. Knop-Gericke, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Germany |
| Correspondent: | Click to Email |
In this presentation I will describe the application of near ambient pressure photoelectron spectroscopy (NAPXPS) to the investigation of electrochemically active gas-solid and liquid-solid interfaces during electrochemical processes. Understanding the oxygen evolution reaction (OER) on a molecular level has become increasingly important over the last few years, beacuse energy storage of renewables is becoming more relevant now that CO2 emission has been identified as a source of climate change.
Nafion membrane based NAPXPS experiments performed on Pt electrodes during the OER demonstrate that Pt oxides are detrimental for the OER. An oxygen induced species characterized by an Pt4f binding energy 0.6 eV above the metallic Pt4f peak was observed. However, these experiments were done in water vapor and the relevance of the results for the OER in liquid water is questionable [1]. Therefore a new approach to study the liquid-solid interface during an electrochemical process in liquid water was developed.
In this new process the electrode material is deposited on a bilayer of graphene that is stabilized by a silicon nitride window with a pinhole structure. The electrode is exposed to the aqueous electrolyte and is irradiated at the same time by synchrotron light through the bilayer graphene membrane. The emitted photoelectrons have to pass the graphene membrane before being detected in the photoelectron analyzer [2]. Recent progress in the study of the electronic structure of noble metal electrodes used in OER reaction will be discussed [3,4].
References:
1. R. Arrigo et al., In Situ Study of the Gas-Phase Electrolysis of Water on Platinum by NAP-XPS, Angew. Chem. Int. Ed. 52, 11660-11664 (2013)
2. J. J. Velasco-Velez et al., Photoelectron spectroscopy at the graphene-liquid interface reveals the electronic structure of an electrodeposited cobalt/graphene electrocatalyst, Angew. Chem. Int. Ed. 54, 14554-14558 (2015)
3. V. Pfeifer et al., The electronic structure of iridium oxide electrodes active in water splitting, PCCP, 18, 2292-2296 (2016)
4. V. Pfeifer et al., The electronic structure of iridium and its oxides, Surf. Interface Anal., 48, 261-273 (2016)