Oferta de Empleo

PhD topic (October 2017 - October 2020)
“Development of nanostructured materials as anodes for SOFC operating directly under hydrocarbon combustible”

Most fuel cells use hydrogen as fuel, but it is not a primary energy source and problems of production, distribution and storage arise. The development of solid oxide fuel cells (SOFCs) using directly a hydrocarbon fuel could lead to an alternative technological advance. Due to a high operating temperature (800-1000 °C), a SOFC can be fed directly with hydrocarbon (e.g., methane) at the anode without using an external reformer hence providing a better heat exchange between the steam reforming reaction (CH4 + H2O → CO + 3H2) and the electrochemical oxidation of hydrogen (2H2 + O2 → 2H2O). Ceramic/metal (cermet) composites such as Ni/YSZ (YSZ = yttrium-stabilized zirconia) are the standard anode materials for a SOFC fed with H2. The metal phase acts as an electronic conductor and a catalyst for the oxidation of the fuel. The use of nickel is problematic when the cell is fed directly with hydrocarbon because the anode is then the site of a deposition of carbon (coking) which strongly deactivates it. An alternative to avoid this deactivation is to replace the cermet with a mixed ionic and electronic conductive oxide (MIEC) which is stable under a reducing atmosphere at high temperature.

MIEC layered perovskites will be explored for this purpose. We propose to improve the electrocatalytic properties of these MIECs by doping and in situ formation of nanocomposite anodes via the exsolution under hydrogen at high temperature of electroactive nanoparticles. In addition to the synthesis of these new materials, the techniques used will be thermal analysis (TGA/DTA) and thermodiffraction (X-rays and neutrons) under various gas streams to study structural and microstructural evolution and chemical reactivity with the most usual electrolytes. Electron microscopy (scanning and transmission) and X-rays or neutron total scattering combined with EXAFS spectroscopy will be used to characterize the local order, as well as X-ray photoelectron spectroscopy (XPS). An important part of the study will be dedicated to the analysis of the surface and the microstructure (including in operando conditions) which govern the electrocatalytic properties. The applicability of these compounds as anode materials will be tested in the scope of existing national and international collaborations. Let us underline the enthusiasm of industrialists to welcome the PhD student in order to test the materials developed at Rennes in prototype cells.

Applicant’s profile
Master 2 in Materials Science or Materials Chemistry. Fluency in oral and written English

Doctoral contract (French Ministry of Higher Education and Research): ~1400 euros/month (net)

Host laboratory
Solid State Chemistry and Materials group, Institute of Chemical Sciences at Rennes, UMR CNRS- University of Rennes 1 No. 6226, Bât. 10B, Campus de Beaulieu, 35042 Rennes, France https://iscr.univ-rennes1.fr/csm/


Dr. Olivier Hernandez (Associate Professor at the University of Rennes 1)  olivier.hernandez@univ-rennes1.fr    (+33223235635)
Dr. Mona Bahout (Associate Professor at the University of Rennes 1)  mona.bahout@univ-rennes1.fr    (+33223236981)
Involved researcher: Dr. Carmelo Prestipino (CNRS researcher)