Center for Functional Nanomaterials Seminar

While the attributes of SOFCs are strong, there are several significant improvements in the materials selection, performance, lifetime, stability and cost reduction necessary until they are fully integrated in the mainstream of power generation. These are complex electrochemical devices under active development with sophisticated materials both in composition and microstructure. Results from the testing and especially the micro-characterization (a critical link between properties and performance) of single planar SOFCs will be presented. The preparation of TEM samples suitable for HR imaging is very challenging; preliminary results will be shared. The emphasis is given to ageing mechanisms responsible for the decrease in their electrical performance during operation, which strongly depend on materials, microstructures and operating conditions.
Advanced EM techniques are essential for characterizing interfaces, defects, nanoparticles, nanophases and bulk materials. TEM can provide imaging, diffraction and spectroscopic information, either simultaneously or in a serial manner and ensures the greatest capabilities for characterizing the physicochemical nature of materials, determine the presence of defects, elemental compositions, shapes, surface structures and even electronic states. It is critical to the fundamental studies of importance to nanoscience and nanotechnology.
For the operation of a PEM fuel cell with pure H2 and air, Pt is the most active catalyst. The logistics involved with delivery and storage of H2 fuel are major hurdles. Cells operate with a reformate fuel in which case a CO tolerant catalyst is required. HRTEM of novel electro-catalyst nanoparticles (RhxSy, RuxSey, Se/Ru, Se/Ru-Mo/C and also Pt) will be presented. The objective is to better understand the structure and arrangement of these materials because their reactivity directly depends on it. The lack of precise structure knowledge makes theoretical calculations and modeling impossible.