Description du projet
Des catalyseurs naturels pour améliorer les piles à combustible solaires
L’exploitation de l’énergie solaire pour produire des formes durables de carburant telles que l’hydrogène nécessite des photocatalyseurs capables d’utiliser efficacement la lumière visible pour diviser les molécules d’eau par électrolyse. De même, afin de permettre la réduction de l’oxygène en eau, une étape cruciale pour la production d’électricité dans les piles à combustible, il est indispensable de disposer de catalyseurs efficaces qui accélèrent la réaction avec des pertes d’énergie minimales. Financé par le Conseil européen de la recherche, le projet Cu4Energy étudiera des catalyseurs naturels tels que l’enzyme à cuivre Laccase, en raison de son fonctionnement rapide et de ses faibles besoins en énergie. Les chercheurs associeront la structure du catalyseur à l’activité catalytique et analyseront le paysage énergétique du cycle de réaction. Les résultats du projet devraient améliorer la connaissance fondamentale et permettre de concevoir des catalyseurs au cuivre très actifs pour les réactions de division et de réduction de l’oxygène.
Objectif
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.
Champ scientifique
- natural scienceschemical sciencesorganic chemistryorganic reactions
- natural scienceschemical scienceselectrochemistryelectrolysis
- natural scienceschemical sciencescatalysis
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
- engineering and technologyenvironmental engineeringenergy and fuelsenergy conversion
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
2311 EZ Leiden
Pays-Bas