PhD Candidate (M/F) in Physical Chemistry and Materials Science: Experimental and Theoretical Study of CO₂ and H₂ Adsorption in Type I Porous Liquids

Job Description

Thesis Subject

The reduction of carbon dioxide (CO₂) emissions and the development of clean energy carriers such as hydrogen (H₂) are major challenges in the energy transition. Current gas capture and separation processes mainly rely on solid porous materials (zeolites, MOFs, activated carbons) or liquid solvents, but these approaches present limitations in terms of regeneration and stability. Porous liquids represent an emerging class of materials that combine permanent molecular cavities with the fluidity of a liquid. They thus open new perspectives for gas capture and separation in continuous processes.

Polyhedral oligomeric silsesquioxanes (POSS) are hybrid organic–inorganic molecular cages based on a siloxane Si–O–Si core surrounded by functionalizable organic groups. Their chemical modularity makes them promising molecular building blocks for the design of porous liquids. The ANR POSS-CO2FEE project aims to develop new POSS-based porous liquids for the selective capture of CO₂ and the separation or purification of hydrogen. This PhD project will focus on the experimental study and modeling of sorption phenomena in these systems.

Your Work Environment

The PhD work is structured around several main objectives: (i) to characterize the POSS-based porous liquids developed within the project; (ii) to study the sorption of gases (CO₂, H₂, N₂, CH₄) and vapors (water and solvents with increasing polarity); (iii) to understand the mechanisms of sorption and diffusion; (iv) to establish relationships between molecular structure and adsorption properties; and finally (v) to combine experiments and simulations to predict the performance of new porous liquids.

Adsorption properties will be investigated using volumetric gas sorption in order to determine adsorption isotherms over a wide range of pressures and temperatures. Dynamic Vapor Sorption (DVS) will be used to study the sorption of water vapor and organic solvents, as well as adsorption and desorption kinetics. Gas mixture experiments will enable the evaluation of selectivity for relevant separations such as CO₂/N₂ or CO₂/H₂. The thermodynamic study may be complemented by adsorption microcalorimetry measurements.

Molecular modeling will be used to interpret experimental results at the molecular scale. Grand Canonical Monte Carlo (GCMC) simulations will be performed to predict adsorption isotherms and selectivities. Molecular dynamics simulations will be used to investigate diffusion mechanisms in porous liquids. Density Functional Theory (DFT) calculations will allow analysis of specific interactions between gas molecules and POSS cages.

**Scientific Environment**
The PhD will be carried out at the Institut Charles Gerhardt Montpellier (ICGM), at the École Nationale Supérieure de Chimie de Montpellier (ENSCM), within the framework of the ANR POSS-CO2FEE project, which involves several partners specialized in the synthesis of POSS cages, the characterization of porous materials, and molecular modeling.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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