Electrochemical behavior and performances of Ni-BaZr 0·1 Ce 0·7 Y 0.1 Yb 0.1 O 3−δ cermet anodes for protonic ceramic fuel cell

International audienceHigh performance Ni-BCZYYb cermet anode were prepared at 1300 °C using electrolyte powders prepared by combustion and commercial NiO. The cermets are porous (39 vol% of porosity), show a high electronic conductivity (1097 S cm−1) and sufficient mechanical properties. The electrochemical behavior of the Ni-BCZYYb/BZCYYb-ZnO/Ni-BCZYYb symmetrical cell elaborated by co-pressing and co-sintering was investigated using electrochemical impedance spectroscopy. The impedance spectroscopy study show that the electrode reaction involves three steps. The total polarization Area Specific Resistance decreases by about one order of magnitude when increasing the temperature from 450 to 600 °C or the H2 concentration from 5 to 100 vol% to reach 0.049 Ω cm2 at 600 °C under pure hydrogen

Hydrogen diffusion in high temperature proton conducting ceramics

BaCeO3 or SrCeO3-based perovskites doped with a rare earth are high temperature protonic conductors (HTPC) envisioned as electrolytes for fuel cells working at intermediate temperature (400–600 C). In these ceramics, the proton conductance is hampered by microstructural defects that act as barriers for hydrogen diffusion. Respective contributions of bulk and grain boundaries to overall conductivity is usually evidenced via impedance measurements but further information on hydrogen transport relevant for improvement of microstructure design can be obtained with nuclear microanalysis, based on the use of MeV light ions microbeam. We report here a contribution of ion beam microanalysis to the study of hydrogen transport in BaCe0.9Y0.1O3. ERDA hydrogen profiling performed on partially hydrated samples at 200 and 500 C reveals concentration gradients from which diffusion coefficients have been derived with the help of a simple Fickian diffusion model

Recherche-action dans un processus de planification territoriale participative. Le SCOT de Thau (France)

Regional and urban planning in France tends to be more distributed due to the decentralisation process but also more integrated and more participative. This is the case for coastal areas where a new type of integrated planning approach start to be experimented on several test areas, including the Thau territory. This area is subject to high pressures which generate numerous conflicts. To cope with these issues, new urban and water planning documents based on a sustainable development project are currently elaborated in a participatory way. Our research teams are supporting the leading institution to organise and evaluate the participatory process. In this paper, the context of the Thau territory is presented after a brief overview of spatial planning in France. Then, emphasis is put on the participatory process itself as well as on tools and methods that are used to support it. Yet the evaluation of this process is discussed