Missions

Efficient carbon dioxide reduction to useful molecules such as carbon monoxide, formic acid, formaldehyde or methanol, stands as an important challenge and would allow decreasing our reliance on fossil fuels while concurrently curtailing our primary sources of carbon-based feedstock chemicals for materials synthesis. 3d transition metal complexes of Fe, Co and Ni with phthalocyanine, porphyrin and polypyridine ligands present high electrocatalytic activity for CO2 reduction but they are predominantly limited to CO formation.1 On one hand, activation of CO2 with molecular catalysts to form highly reduced products such as methanol or formaldehyde are rare. On the other hand, heterogenization of these molecular catalysts on the surface of photoelectrodes have achieved limited success. In this program, we will explore the integration of CO2 reduction catalysts into multifunctional polymer hydrogels to capture the benefit of this immobilization technique and to boost their performances and their stabilities. We surmise that the side chain pendent groups on the polymer backbone will permit to: i) control the environment of the catalyst, such as permittivity, hydophilicity and proton transport; ii) stabilize the transition states and reactional intermediates thanks to the moieties situated in the second coordination sphere and iii) facilitate the CO2 mass transport within the hydrogel matrix. Indeed, it is well-documented that CO2 reduction activity is drastically affected by the catalyst environment as it is the case in many redox enzymes, whose protein scaffold modify the activity of the active catalytic center.2 Our goal in this program is therefore to mimic, in a simpler manner, the function of the protein matrix surrounding with a co-polymer imbedding a good CO2 reduction catalyst, a proton relay, and suitable functional groups to stabilize transition state during catalysis and provide a good solubility of CO2 within the polymer gel. This approach, rarely explored, is based on preliminary results of some members of the consortium3 and promises exciting and original outcomes. It will be investigated with a consortium of 4 international groups such as Fabrice Odobel at Nantes University, Marc Robert at Paris Cité University, Nicolas Plumeré at Technical University Munich and David Tilley at the University of Zurich. Overall, the main objective of the present project is to develop innovative catalytic materials based on smart hydrogels deposited on semiconductor photoelectrodes for CO2 reduction containing well-positioned functional groups in order to reach outstanding, unprecedented performances that can find valuable uses in the sectors of energy and chemical industry.
References:
(1).Dalle, K. E.; Warnan, J., et al. Electro- and Solar-Driven Fuel Synthesis with First Row Transition Metal Complexes. Chem. Rev. 2019, 119, 2752.
(2).Amanullah, S.; Saha, P., et al. Biochemical and artificial pathways for the reduction of carbon dioxide, nitrite and the competing proton reduction: effect of 2nd sphere interactions in catalysis. Chem.Soc. Rev. 2021, 50, 3755.
(3).(a) Pati, P. B.; Wang, R., et al. Photocathode functionalized with a molecular cobalt catalyst for selective carbon dioxide reduction in water. Nature Commun. 2020, 11, 3499.; (b) Wang, R.; Boutin, E., et al. Carbon Dioxide Reduction to Methanol with a Molecular Cobalt-Catalyst-Loaded Porous Carbon Electrode Assisted by a CIGS Photovoltaic Cell. ChemPhotoChem 2021, 5, 705.; (c) Li, H.; Münchberg, U., et al. Suppressing hydrogen peroxide generation to achieve oxygen-insensitivity of a [NiFe] hydrogenase in redox active films. Nature Commun. 2020, 11, 920.

Activités

The main activity of this post-doctoral position is to prepare and develop novel co-polymer hydrogels containing molecular catalyst and diverse functional groups that will tested for the electro- and then to the photo-catalytic reduction of CO2. The candidate will be involved in the following tasks:
1- Synthesis of methacrylate-based monomers containing: molecular catalysts, acidic moieties, hydrophilic units and second coordination sphere (such as ammonium group). It requires high skills in organic synthesis and coordination chemistry.
2- Preparation of the polymers by radical co-polymerization of the above monomers, requiring an real experience in polymer chemistry.
3- Investigate the electro- and photocatalytic performances of the synthesized materials with secondments in partners' laboratories.
4- Presentation of results at progress meetings with the consortium.
5- Writing of reports (bibliography and experimental results).

Compétences

We are searching for a highly motivated, creative researcher holding a PhD in chemistry and particularly in polymer chemistry interested by a multidisciplinary project merging organic synthesis, polymer chemistry and electrocatalysis. The candidate must be particularly skilled in organic synthesis and particularly in polymer science and competences in electrochemistry are also of interest. For example, a previous experience with radical polymerization or polymer synthesis is crucial. Moreover, the candidate should be self-motivated and able to conduct fast paced research and work independently in a team-oriented environment. The researcher will be hosted in a friendly group and should be ready and happy to participate in team work.

Contexte de travail

The project will be carried out in Fabrice Odobel' group located in the CNRS laboratory CEISAM, which is part of Nantes University in France. The team is currently composed of 5 permanent researchers, 2 post-doctorates and 6 PhD students. The CEISAM Institute ("Interdisciplinary Chemistry: Synthesis, Analysis, Modelling") encompasses all the research activities carried out in the area of molecular chemistry in Nantes and its surroundings. The CEISAM Institute is located on the Faculty of Science campus of the University of Nantes. CEISAM has about 3,000 m2 of space, and hosts about 140 researchers with different backgrounds, specialized in the fields of chemistry, material sciences, hybrid materials, electrochemistry, photochemistry, methodological developments in analytical chemistry, and molecular modelling. The laboratory has all the latest equipment and characterizations for organic synthesis, polymer chemistry and coordination chemistry (NMR and mass spectrometers, electrochemistry bench, photoelectrochemistry, multiple chromatography equipments, etc.) .

Contraintes et risques

No specific risks other than those of a chemical research laboratory.