Skip to Main content Skip to Navigation
New interface
Theses

Hydrogénases artificielles : nouveaux catalyseurs biosynthétiques pour la production d'hydrogène

Abstract : Hydrogen production, through the reduction of water in electrolysers, is currently one of the most convenient ways to store energy durably, if the electrical energy is initially obtained from renewable resources. However, while electrolysis is a mature and robust technology, the most promising devices, based on proton exchange membranes, relay on the use of platinum as electrocatalyst to accelerate both hydrogen evolution and water oxidation reactions. This rare and expensive metal is not itself a renewable resource, so the viability of a hydrogen economy depends on the design of new efficient and robust electrocatalytic materials based on earth-abundant elements. A competitive alternative to platinum could be found in living micro-organisms metabolizing hydrogen thanks to hydrogenases. Catalysis in hydrogenases only requires base-metal centers (nickel and iron) thus holding promises for the development of earth-abundant H2-evolving catalysts but these enzymes are highly oxygen sensitive and difficult to rproduce in large quantities under an active form. Biomimetic and bioinspired chemistry can use the structure of their active sites as an inspiration to design new synthetic catalysts and could produce dinuclear nickel –ion or diiron and cobalt complexes as active H2 evolving catalysts, respectively. In particular cobaloximes and cobalt diimine–dioxime complexes are efficient and stable electro-catalysts for hydrogen evolution form acidic nonaqueous solutions or in mixtures of water and a non-aqueous solvent. Until now, only few studies on H2 evolution catalyzed by these Co complexes have been reported. In this work we use the biosynthetic approach, consisting in producing biohydrid systems combining a synthetic catalyst with a host protein. The protein framework is expected to provide the catalyst with enhanced solubility in water, to proect it against side reactions leading to decomposition and, ultimately to improve its catalytic performances. We selected hemoproteins (myoglobin and heme oxygenase) as host proteins and studied the formation of adducts with cobaloximes and cobalt diimine–dioxime complexes. We first describe the method used to produce the apo-form of myoglobin ( ie the protein without its naturel cofactor, heme) and then describe the preparation and characterization of various hybrids in which the cobalt complexes are bound to the protein thanks to the coordination of the imidazole group of a histidine residue. The hybrids proved stable in solution and display catalytic activity for hydrogen production in fully aqueous solution. We also showed that the protein framework tunes the catalytic activity for of the cobalt complex. These novel biohybrids can thus be named as artificial hydrogenases.
Document type :
Theses
Complete list of metadata

Cited literature [47 references]  Display  Hide  Download

https://theses.hal.science/tel-00949342
Contributor : ABES STAR :  Contact
Submitted on : Wednesday, February 19, 2014 - 3:07:09 PM
Last modification on : Friday, March 25, 2022 - 9:43:29 AM
Long-term archiving on: : Monday, May 19, 2014 - 12:45:30 PM

File

37678_BACCHI_2013_archivage.pd...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00949342, version 1

Collections

Citation

Marine Bacchi. Hydrogénases artificielles : nouveaux catalyseurs biosynthétiques pour la production d'hydrogène. Sciences agricoles. Université de Grenoble, 2013. Français. ⟨NNT : 2013GRENV027⟩. ⟨tel-00949342⟩

Share

Metrics

Record views

351

Files downloads

733