Catalyst recycling: Identification of key parameters for the extraction of critical metals by leaching

In a context of increasingly tight resource management, the hydrometallurgy process is now essential for metal recycling. Hydrometallurgy involves dissolving the various metals contained in a material in aqueous solution, then separating them to recover them. The first stage of the process, leaching (or dissolving the metals), must be carefully optimized to save on the quantities of solvent used and also, in the case of heterogeneous catalysts, to avoid damaging the support. Indeed, it avoids contaminating the extraction solution and enables it to be reused in a short loop for the re-impregnation of new catalysts. The aim of this thesis is to use spectroscopic methods (Raman, X-ray absorption, etc.) to determine the critical parameters that optimize the extraction of the metals most resistant to leaching without damaging the catalyst support (based on alumina). The first stage of the work will involve synthesizing reference materials and developing the method for quantifying Mo- and Co-based species. The second part will involve in situ monitoring of leaching using X-ray absorption spectroscopy in order to identify the most refractory species in crystalline form or in strong interactions with the support. This methodology will then make it possible to study the impact of various parameters (nature of the solvent, temperature, etc.) that will improve the extraction of critical metals from the real catalyst. The final stage of kinetic and thermodynamic modelling of the physico-chemical phenomena involved will be carried out using PhreeQC software, based on the data acquired during the thesis.

Keywords: Metal recycling, Circular Economy, Catalyst, Spectroscopies, Modelling

• Academic supervisor    Dr Elodie DEVERS, IFPEN
• Doctoral School    ED34 EDML, Université Claude Bernard Lyon I
• IFPEN supervisor    Dr Olivier DELPOUX, ORCID : 0000-0002-1166-5476
• PhD location    IFPEN , Solaize, France  
• Duration and start date    3 years, starting in the fourth quarter 2024 (Novembre 4)
• Employer    IFPEN
• Academic requirements    University Master degree in Catalysis or Chemistry    
• Language requirements    English level B2 (CEFR)    
• Other requirements    Catalysis, Material chemistry, Spectroscopy

To apply, please send your cover letter and CV to the IFPEN supervisor indicated below.