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Reference : UMR7285-STEBAR-003
Workplace : POITIERS
Date of publication : Tuesday, July 20, 2021
Scientific Responsible name : Stève Baranton
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 October 2021
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
This Ph.D. research work will be performed in the context of the "Gluconic" ANR project which proposes to study the electrocatalytic conversion of glucose into molecules of interest for fine chemistry. It involves 5 research laboratories in France: the LEPMI at Grenoble and the IC2MP at Poitiers where the research work will take place, and the LGC at Toulouse, the ICPEES and the IC at Strasbourg. The research for this Ph.D will be divided into different steps.
The first part will consist in the synthesis and characterization of nickel based electrocatalytic materials with a 3-D porous structure. For these 3-D electrodes, carbon and nickel foam as well as nickel felt will be used as support. A nickel-based nanostructure will be added to these supports, either by electrodeposition or by grafting nanoparticles prepared by colloidal synthesis. After the catalyst preparation, their morphology, structure, composition and surface will be characterized by physical (SEM, TEM, XRD, ICP-OES, XPS, etc.) and electrochemical (cyclic voltammetry in support electrolyte) methods.
The second part will be the study of the electrocatalytic behavior of these electrodes in a three-electrode cell for oxidation and reduction of glucose. The aim will be the identification of active materials for anode and cathode before the selectivity study. The most active materials will be by in situ FTIRS and DEMS to study their selectivity and select the electrocatalyst presenting the best compromise between activity and selectivity for molecules of interest from glucose.
The third part will consist in transferring the selected materials in a two electrodes electrolysis cell operating in batch mode with anolyte and catholyte recirculation. This electrolysis cell will be used to obtain a high concentration of glucose reaction products formed on both electrodes for their identification and quantification (by HPLC, NMR and MS). This step will be more sensitive to the 3-D porous structure of the electrodes than previous characterizations in three- electrode electrochemical cell and will allow a refinement of the catalytic activity and selectivity data of the electrode materials. These results will be transmitted to the LGC in Toulouse and will help in the progression of the ANR project towards its final step which will consist in integrating the selected catalytic materials in a continuous flow electrolysis cell.
The last part will be the study of the selected electrode materials stability by accelerated ageing in three-electrode cell. This study will allow the determination of the ageing mechanism of nickel-based electrodes. Furthermore, a postmortem study of the electrode used in the batch cell and the continuous flow cell will be performed by physical characterization methods (SEM, TEM, XRD, ICP-OES, XPS, etc.) to evidence the effects of a long-term electrolysis on electrode ageing. From this study, mitigation solutions will be proposed to limit electrode degradation and performance loss in electrolysis cell.
Finally, in addition to being done between two laboratories (the LEPMI at Grenoble and the IC2MP at Poitiers), the Ph.D. student will have to collaborate with two other Ph.D. students hired in the three other labs involved in the project for the electrode preparation and the characterization of electrode materials (activity and selectivity).
The IC2MP (UMR CNRS 7285, University of Poitiers) is internationally recognized for its expertise in synthesis of nano-electrocatalysts with controlled shape, composition and structure and their characterization by physical characterization methods (SEM, TEM, XRD, ICP-OES, XPS, etc.), by operando methods (FTIRS). They have a long experience in the study of electrooxidation/reduction of bio-sourced compounds in two- and three-electrode electrochemical reactors coupled with analytical methods (HPLC, NMR) and adapted for electro-reforming of biomass derivatives.
The LEPMI UMR 5279 CNRS - Grenoble INP - University Grenoble Alpes pioneered degradation studies of (including alkaline) fuel cell/electrolyzer electrocatalysts and built a complete platform enabling such characterizations. Tools range from electrochemical techniques, coupled spectroscopies (DEMS, ICP-MS) and microscopies (IL-TEM), allowing studies of materials in close-to-real experimental conditions. The LEPMI has developed an expertise in the synthesis and characterization of nickel based 3-D structures for electrocatalytic applications.
Constraints and risks
There are no particular constraint or specific risk associated with this research work.
Required and preferred skills from applicants:
- Have a master's degree or an engineering diploma at the date of the PhD beginning, preferably in the fields of electrochemistry and materials science.
- Have a good scientific and technical English skill (written and oral)
- Have good communication and teamwork skills and have the ability to present clearly his results (in French and English)
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