Summary:
The development of renewable energy sources is of paramount importance in meeting the energy challenge of the 21st century. Molecular hydrogen's ability to store and transport energy makes it an ideal energy carrier. It is at the heart of research aimed at replacing fossil fuels with responsible, environmentally-friendly alternatives. However, its production method generates significant carbon dioxide emissions, hindering its large-scale integration. A more environmentally-friendly alternative would be to produce it by electrolysis of water, although this method remains costly due to the materials used, which are generally platinum- and iridium-based. Current research is aimed at replacing these expensive noble metals with affordable, sustainable alternatives. The aim of this thesis was to develop molecular catalysts based on non-noble and abundant metals for hydrogen production under mild environmental conditions. The approach taken was to draw inspiration from hydrogenases, biological systems capable of reversibly converting hydrogen, to effectively reproduce natural processes in artificial systems.
Thesis work thus focused on the design of original bio-inspired catalysts, based on non-innocent thiosemicarbazone ligands, with the aim of understanding the impact of their structure on catalytic properties. By playing on the nature and position of the substituents decorating the thiosemicarbazone ligand, several metal complexes, based on nickel and cobalt, were prepared and evaluated for their ability to promote the electrocatalytic reduction of protons to hydrogen. Our studies were also extended to the exploration of different experimental conditions, including the choice of proton source and solvent, with the aim of identifying the most favorable parameters for hydrogen production. This work has enabled us to gain a better understanding of the relationship between molecular structure and catalytic activity, and to identify promising combinations for the development of high-performance molecular catalysts for the electrocatalytic conversion of protons into hydrogen. Our results pave the way for the integration of these catalysts in solid matrices to improve their performance, stability and durability in electrocatalytic hydrogen production.
Co-supervisors :
- Maylis ORIO (iSm2)
- Renaud HARDRE (iSm2)