Description of the thesis topic

The energy transition requires the development of efficient, low-carbon energy storage and conversion systems. In this context, hydrogen (H₂) is a promising energy carrier. Ideally, it should be produced by water electrolysis using intermittent renewable energy sources and then used in a fuel cell to generate electricity. To date, proton exchange membrane water electrolyzers (PEMWEs) are the most efficient and technologically mature systems for hydrogen production. However, PEMWEs require noble metals (Pt, IrOx) for electrocatalysis, which poses a significant resource challenge. Efficient recycling is therefore essential for the large-scale deployment of this technology.

The RECAT-H₂ project, part of the PEPR Recycling program, aims to develop environmentally friendly processes to recover Pt and Ir from PEMWEs in a closed-loop approach. Hydrometallurgical and electrochemical leaching methods will be investigated. Non-conventional media, such as deep eutectic solvents, may also be considered. This PhD project includes the refabrication of electrocatalysts with performance comparable to the state of the art, requiring an in-depth understanding of the underlying physicochemical mechanisms.

Work Context

This PhD project will involve two partners: LEPMI in Grenoble, the main host laboratory for the thesis, and CEA LITEN in Grenoble.

At LEPMI, the research will focus on exploring the chemical and electrochemical conditions for leaching Pt and IrOx nanoparticles originating from aged electrolyzer cores, notably through the use of in situ and operando methods coupled with electrochemistry. The refabrication of electrocatalysts will be guided by minimizing their environmental footprint guided by life cycle assessment (LCA).

Research stays at CEA LITEN will contribute to the selection of an efficient IrOx extraction process through its expertise in non-conventional solvents, such as deep eutectic solvents (DES), and will support the scale-up of the PEMWE core refabrication process. The recycled electrodes will be tested in single-cell configurations for validation.

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.