Projektbeschreibung
Bessere Modelle für Prozesse an der Grenzfläche zwischen Elektroden und Elektrolyten
Den zunehmenden Energiebedarf der Welt auf nachhaltige Weise zu decken, stellt eine der größten Herausforderungen unserer Zeit dar. Bei vielen Energiespeichern und Energieerzeugungsvorrichtungen gilt die Elektroden-Elektrolyt-Grenzfläche als kritische Komponente. Hier finden der Ladungstransfer, die Elektrolytzersetzung und die Elektrodendegradation statt. Da Ionen aus der Elektrolytlösung an der Oberfläche der Elektrode haften, getrennt von den Ladungen in der Elektrode selbst, bildet sich eine sogenannte elektrochemische Doppelschicht. Diese Struktur spielt bei elektrochemischen und elektrokatalytischen Reaktionen eine entscheidende Rolle. Das EU-finanzierte Projekt FRUMKIN entwickelt nun mithilfe einer umfassenden Kombination aus experimentellen, theoretischen und rechnerischen Verfahren ein neues Modell der an der elektrochemischen Doppelschicht ablaufenden Prozesse.
Ziel
The FRUMKIN project aims to develop and test a new model for the electric double-layer structure of the electrode-electrolyte interface and to investigate the impact of this double-layer structure on the kinetics and selectivity of electrochemical and electrocatalytic reactions. The inspiration for this new model comes from my own recent work that the classical Gouy-Chapman-Stern model for the electric double layer fails to properly describe the interface between an aqueous electrolyte and single-crystal platinum and gold electrodes. Specifically, our results indicate that there is an attractive interaction between ions and the electrode surface (unaccounted for in the Gouy-Chapman-Stern theory) that accumulates ions in the diffuse double layer, and that ions in the double layer interact with the electrode and with themselves through water-mediated hydration forces, approximately following the Hofmeister series. These effects are observed even for low electrolyte concentrations, explaining the invalidity of the Gouy-Chapman-Stern theory.
The FRUMKIN project will approach its research objectives using a variety of high-level experimental, spectroscopic, theoretical, and computational techniques. The heart of the experimental work is based on ac voltammetry, i.e. differential capacitance measurements of the various interfaces, and electrochemical measurements of reactivity. Modelling of the experimental differential capacitance curves is based on first-principles DFT calculations and coarse-grained free-energy-based classical density functional simulations of the double-layer properties. Experimental molecular details of both double-layer structure and reactivity will be obtained from in situ vibrational spectroscopy (Infrared and Raman) and advanced in situ X-Ray spectroscopy, specifically Near-Ambient Pressure X-Ray Photoelectron Spectroscopy and Total Electron Yield X-Ray Absorption Spectroscopy.
Wissenschaftliches Gebiet
- natural sciencesphysical sciencesquantum physics
- natural scienceschemical sciencescatalysiselectrocatalysis
- natural sciencesphysical sciencesmolecular and chemical physics
- natural sciencescomputer and information sciencescomputational sciencemultiphysics
- natural sciencesmathematicsapplied mathematicsmathematical model
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-ADG - Advanced GrantGastgebende Einrichtung
2311 EZ Leiden
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