My research activities concern the experimental and theoretical modeling of the structure, properties and reactivity of molecular architectures in the
field of bio-inorganic chemistry and having applications in biology and catalysis (organic radicals, metal complexes of transition, active sites of metalloproteins). Since 2015, I have been interested in molecular catalysts allowing the production of hydrogen electrochemically or photochemically. Computational chemistry is an important part of this research subject. By relying on tools of quantum chemistry, I aim in particular to: (i) a better understanding of the reaction mechanisms (ii) the prediction of the catalytic performances of the systems and (iii) the development of new synthetic targets.
References: Chem. Eur. J., 2022 - Chem. Comm., 2021.
1) Bio-inspired hydrogen production: molecular electrocatalysis, photocatalysis and supported catalysis
By combining non-innocent ligands and Earth-abundant transition metal ions, we have developed a family of bio-inspired complexes active in electrocatalytic proton reduction. We have shown that these complexes exhibit high electrocatalytic activity for the reduction of protons to hydrogen. However, their performances would still benefit from being improved knowing that the key elements to understand, rationalize and improve their reactivity remain unknown. A first axis (pillar of this research theme) aims at continuing our work to predict, from a theoretical point of view, the catalytic performances of our bio-inspired complexes and to design, from an experimental point of view, more efficient molecular catalysts.
A second axis aims at including catalytic centers in a solid matrix, in order to make them stable and economically profitable electrodes for producing hydrogen by electrolysis in aqueous media. Our first results have showń the relevance of combining a molecular catalyst with a solid polymer matrix to develop efficient bio-inspired catalytic systems for the electrochemical and photochemical conversion of protons to hydrogen. We aim to design new innovative eco-compatible supported catalysts to solve the problem of finding new energy sources.
A last axis consists in the development of systems without noble metals for the photocatalytic production of hydrogen, thus allowing the conversion of solar energy into chemical energy. We will combine organic photosensitizers with inorganic catalysts capable of producing dihydrogen. We aim to design robust and flexible coupling devices capable of capturing light to deliver electrons to the catalyst and produce hydrogen. To do so, we will consider two different routes, namely the improvement of our photo-catalytic systems and the design of dyads as novel photocatalysts for light-initiated hydrogen production.
Funding : ANR JCJC, ANRT, DGA, Région Sud, IEA CNRS
Participants : Renaud Hardré, Bruno Faure, M. Réglier, Julien Massin
Collaborations : Company Rener, Athanassios Coutsolelos (Univ. Crete), Kalliopi Ladomenou (Univ. International Hellenic), Michel Sliwa (Univ. Lille), Vera Krewald (Univ. Darmstadt)
Publications : Chem. Eur. J., 2018 - Chem. Sus. Chem., 2019 - Dalton Trans., 2020 - RSC Adv., 2021 - Chem. Phys. Chem., 2022.
2) Oxygen activation: Structure-function studies of copper monooxygenases
Lytic Polysaccharide Monooxygenases (LPMOs) are copper metalloenzymes that catalyze the oxidative cleavage of recalcitrant polysaccharides such as cellulose, hemicellulose or chitin. LPMOs carry out the hydroxylation of a C-H bond on cellulose thanks to an active site composed of a copper, which leads to the rupture of the glycosidic chain. It should be noted that the glycosidic C-H bond hydroxylated by LPMO is very energetic (BDE > 95 kcal/mol) and many questions still remain about the mode of action, the reaction intermediates and the role of the particular coordination motif ("histidine-brace") on the catalytic properties of the metal ion. We wish to obtain structure-function relationships on this family of copper monooxygenases and to this end, a double approach combining experimental data and theoretical calculations is developed. Indeed, the precise description of the spectroscopic and electronic properties of the copper sites by quantum chemical methods is a prerequisite to analyze the experimental data, understand the mechanistic features and design bio-inspired catalysts. This project proposes to use both an experimental and theoretical approach to probe the structure and properties of copper enzymes. We develop a multidisciplinary approach combining biology, spectroscopy and quantum chemistry to interpret the electronic structure, redox and spectroscopic properties of these enzymes to better understand the properties and function of bioinorganic sites. Our strategy is applicable to predict the structure and properties of copper centers, which will lead to a better understanding of the enzymes and their reactivity.
Fundings : ANR/DFG, PHC Procope, PHC Procope +
Participants : A. Jalila Simaan, C. Decroos, M. Réglier
Collaborations : Sylvain Bertaina (IM2NP, Aix Marseille Univ.), Giuseppe Sicoli (LASIRE, Lille Univ.), Dimitrios Pantazis et Serena DeBeer (MPI Mülheim, Allemagne)
Publications : Chem. Phys. Chem., 2020 - Magnetochemistry, 2022 - Inorg. Chem., 2022.