Projektbeschreibung
Natürliche Katalysatoren für verbesserte solare Brennstoffzellen
Die Nutzung der Solarenergie zur Herstellung nachhaltiger Kraftstoffe wie Wasserstoff erfordert Photokatalysatoren, die sichtbares Licht effizient nutzen können, um Wassermoleküle durch Wasserelektrolyse zu spalten. Auch für die Reduktion von Sauerstoff zu Wasser, einem entscheidenden Schritt für die Stromerzeugung in Brennstoffzellen, werden effiziente Katalysatoren benötigt, um die Reaktion mit minimalen Energieverlusten zu beschleunigen. Im Rahmen des vom Europäischen Forschungsrat finanzierten Projekts Cu4Energy sollen natürliche Katalysatoren wie das Kupferenzym Laccase erforscht werden, da es schnell arbeitet und wenig Energie benötigt. Die Forschenden werden die Katalysatorstruktur mit der katalytischen Aktivität in Verbindung bringen und die Energielandschaft des Reaktionszyklus analysieren. Es wird erwartet, dass durch die Projektsergebnisse das grundlegende Verständnis verbessert und hochaktive Kupferkatalysatoren für Sauerstoffspaltungs- und -reduktionsreaktionen erarbeitet werden können.
Ziel
Water oxidation (WO) and oxygen reduction (OR) are crucial reactions to produce and to consume solar fuels. It is important that WO and OR occur with very high catalytic rates with only a very small thermodynamic driving force (i.e. a small overpotential). In these terms, natural catalysts perform significantly better than the artificial systems. Especially the copper enzyme Laccase operates fast at a low overpotential. In principle one could use the same design principles used in the enzymatic systems to produce artificial catalysts for OR and WO. It is envisioned that for the most ideal OR and WO catalysts:
1. all redox reactions within the catalytic cycle should occur as close as possible to the thermodynamic potential where OR and WO become accessible.
2. Equilibria that are not coupled to redox reactions need to be biased for product formation.
3. Proton shuttles are necessary to manage proton transfer concerted with electron-transfer and electron-transfer coupled to O–O bond cleavage or O–O bond formation.
In this proposal molecular copper catalysts for OR and WO are studied by means of a combined electrochemical and computational approach, taking in account the design principles above. Experiments will be carried out wherein the structure of the catalyst is linked to the observed catalytic activity and the potential energy surface of the catalytic cycle. The proposal is in particular focused on the rate-determining step of the catalytic reaction, as improvements here will directly lead to enhanced catalytic rates. A functional model system of Laccase will be designed to study the rate limiting proton-and-electron-coupled O–O bond scission reaction, which is the rate limiting step in OR by Laccase.
The aim of the proposal is to significantly increase of fundamental understanding of the design principles for molecular OR and WO catalysts and to deliver new and very active molecular copper catalysts for OR and WO at the end of the project.
Wissenschaftliches Gebiet
- natural scienceschemical sciencesorganic chemistryorganic reactions
- natural scienceschemical scienceselectrochemistryelectrolysis
- natural scienceschemical sciencescatalysis
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
- engineering and technologyenvironmental engineeringenergy and fuelsenergy conversion
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-STG - Starting GrantGastgebende Einrichtung
2311 EZ Leiden
Niederlande