Reference : UMR5250-JERFOR-003
Workplace : GRENOBLE
Date of publication : Friday, September 16, 2022
Scientific Responsible name : Marie-Noëlle Collomb
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 1 November 2022
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
Water oxidation into oxygen (OER) remains a bottleneck in the scale-up of water-splitting and CO2-reduction electrolyzers due to slow kinetics and large overpotentials. Key challenges are the development of efficient, robust and cheap earth-abundant OER catalysts and their nanostructuration to improve their efficiency by increasing the active area/volume ratio while reducing the manufacturing cost. Inorganic catalysts based on metal oxides MOx are the most promising OER catalysts in terms of efficiency and stability. Current research is focused on the development of oxides based on abundant metals (Co, Ni, Fe, Mn and Cu), which are less expensive than Ir and Ru oxides and their nanostructuring. In this context, the objective of this research project is to design new nanocomposite electrode materials, active and stable for water oxidation inspired by Photosystem II (PSII). These materials will consist of (sub)nano-sized metal oxides MOx or mixed-metal oxides M(M')Ox (M, M' = Ni, Co, Mn, Fe, Cu…) electrogenerated and well dispersed into a polymer matrix substituted with anionic functions. They will mimic the carboxylates rich environment of the natural Mn4CaO5 cluster of PSII and its sub-nanosized structure, two essential features for an outstanding catalytic efficiency. They will be elaborated on the surface of an electrode by a simple and versatile electrochemical method well mastered in our team. The polymer will have a beneficial effect on the stability of the materials by providing steric confinement and protection of the nanoparticles of M(M')Ox from aggregation and corrosion during electrocatalysis. The methodology will consist in the elaboration of the nanocomposites, the evaluation of the electrocatalytic performance for OER and the associated mechanism, as well as the evaluation of the stability under electrocatalytic conditions by long-term electrolyses. The nanocomposite materials will be also fully physically characterized by several and complementary methods in order to evaluate its morphology, chemical composition, to estimate the size of the particles of metal oxides and their dispersion within the polymer. Some characterizations will be also performed after OER long-term electrolysis in order to evaluate the overall stability.
This research work is funded by the French National Research Agency (ANR), project OERNanoCat and will be carried out in the Département de Chimie Moléculaire (DCM) at the Université Grenoble Alpes (UGA) within the team Electrochimie Moléculaire et Photochimie Redox (EMPRe). This project is built on the recent work of the team on the elaboration of nanocomposite materials for water oxidation (Sustainable Energy Fuels, 2021, 5, 4710-4723. DOI: /10.1039/D1SE00363A and Catal. Sci. Technol., 2018, 8(16) 4030-4043. DOI: 10.1039/C7CY01949A).
The DCM is a joint CNRS/UGA unit (UMR 5250) mobilizing nearly 80 permanent researchers/teachers/ITA/IATOSS and as many doctoral students, post-doctoral students and masters. It is structured in 6 research teams, each with a scientific theme. The EMPRe team has a strong expertise in molecular electrochemistry and redox photochemistry. The research activities manly focus on the activation of small molecules (H2O oxidation into O2 (OER) reduction into H2 (HER), reduction of CO2) by electro- and photo-catalysis using molecular and inorganic catalysts and photosensitizer.
The EMPRe team has all the necessary equipment for electrochemistry and electrocatalysis experiments as well as for oxygen evolution quantification (GC-MS). The characterization of the nanocomposite materials will be carried out via the equipment and platforms of the laboratories of the campus of Grenoble in particular at the Institute of Molecular Chemistry-ICMG (AFM, TEM), ISTerre (ICP-AES) and CMTC INP (SEM-EDX).
The ANR project OERNanoCat involves a collaboration with Benedikt Lassalle at the Synchroton Soleil (Paris) for X-ray absorption spectroscopy (XAS) under in situ and in operando conditions in order to understand and control the formation and OER activity of the nanocomposite materials.
The PhD student will work under the supervision of Dr. Marie-Noëlle Collomb (DR1 CNRS) and Jérôme Fortage (CRCN CNRS).
Constraints and risks
The candidate will be required to handle aqueous or organic solutions containing low toxicity chemicals.
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