Missions

With the increase in CO2 concentration in the atmosphere, there is an urgent need to develop materials to capture this gas in an efficient and durable way. Intense research has been carried out on the international level, and a wide variety of compounds have been studied for this purpose, including porous materials like zeolites and MOFs (Metal Organic Frameworks). However, very often, the exact mode of incorporation of CO2 in the materials is uncertain: physi- or chemi-sorption? formation of carbonates (CO32-) and/or bicarbonates (HCO3-) in the pores? local mobility of CO2 or trapped (bi)carbonates? reactivity in presence of water? Answering these questions and determining the details of the reactivity of CO2 in these materials is a real challlenge.
Among the analytical tools capable of informing on the local structure around CO2 at the atomic level, there is nuclear magnetic resonance (NMR) spectroscopy. Recently, it has been demonstrated that oxygen-17 NMR can allow studying the local structure around CO2 in porous materials. However, these works also showed the intrinsic difficulties related to the interpretation of the spectra.

In this general context, the purpose of this post-doc will thus be:
1- to synthesize cristalline model compounds, of known structure, containing carbonate or bicarbonate ions, which will be labeled in oxygen-17 (as the natural abundance of this isotope is too low for allowing to perform high-resolution NMR analyses without labeling)
2- to characterize the model phases by powder X-ray diffraction, vibrational spectroscopies (IR and Raman), mass spectrometry, and solid state NMR (13C, and of course 17O)
3- to study at different temperatures the 17O NMR signatures of the carbonate and bicarbonate ions (and also the 13C NMR ones), in order to access information on their local dynamics within the crystals, and to make the link with computational models (which will be elaborated using density functional theory and/or molecular dynamics methods) ;
4- to use the solid state NMR observations made on the model materials to interpret the observations made for MOFs entrapping CO2 gas.

Activités

- Development of 17O isotopic labeling reactions, especially using mechanochemistry
- « Routine » analyses of materials (using vibrational spectroscopies, powder X-ray diffraction) and mass spectrometry (to quantify the enrichment level)
- Solid state NMR analyses and data interpretations
- Interactions with scientific collaborators to complete the NMR analysis of the structures, using computational approaches
- Participation to the daily activities in the laboratory, including for the improvement of synthetic and characterization protocols
- Supervision of PhD students and post-doc involved in related studies
- Valorisation of the results, under the form of publications and/or presentations at (inter)national conferences

Compétences

- Expertise in materials chemistry (synthesis and characterisation)
- Experience in solid state NMR (an expertise on quadrupolar nuclei will be seen as a plus)
- Experience in the use of « routine » characterization methods of materials (notably using IR spectroscopy, and powder X-ray diffraction…)
- Excellent level of communication in english (oral and witten), to be able to present and summarize the results under the form of publications, webinars, and presentations at conferences.
- Autonomy and rigour ; team-working

Contexte de travail

Research will be carried out at the Institut Charles Gerhardt (ICGM, UMR5253) of the University of Montpellier (https://www.icgm.fr/), within the MISOTOP research group (https://www.misotoplab.org/).

The ICGM est internationally renowned for its expertise in materials science, with an excellent support for advanced studies on their synthesis and characterization. For the oxygen-17 isotopic labeling, the laboratory is equipped with several machines for mechanochemical synthesis, as well as 3 solid-state NMR spectrometers, all wide-bore (300, 400 et 600 MHz), and numerous MAS NMR probes (with rotor diameters from 1.2 to 9.5 mm), including one specifically dedicated to the project for the development of 17O NMR studies.

On a daily basis, the post-doctoral researcher will be working in a collaborative and interdisciplinary environment, in interaction with the local team of researchers, engineers, and students, directly associated to these studies at the ICGM, but also with the whole team of scientists working on the ANR COMeuFs research project (including from the groups of Dr F. Pourpoint in Lille and Prof C. Gervais in Paris). Moreover, to further gain in sensitivity and resolution, ssNMR measurement campaigns will be planned on the high field instruments available within the Infranalytics national network. (https://infranalytics.eu/en/users/platforms).

This project is funded by the French national funding agency (ANR). Interested candidates should deposit their CV and motivation letter on the CNRS portal, at the following address: https://emploi.cnrs.fr/Offres/CDD. It is also recommended to include in the application the names of 2 references. The starting date for the post-doc should be between august and november 2025.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.