About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Ceramics for Clean Hydrogen
|
| Presentation Title |
Improving Electrode Activity and Stability Through Nanocomposite and Crystal Chemical Strategies |
| Author(s) |
S. Zhang, L.O. Anderson, Y.Y. Hsiau, X. Yu, Alexia Popescu, E. Griffin, L. Lin, Vinayak P. Dravid, K. Hatzell, D. Nordlund, Nicola H. Perry |
| On-Site Speaker (Planned) |
Nicola H. Perry |
| Abstract Scope |
Redox-active ceramic electrodes interfacing with gaseous H2 or H2O need to support rapid surface reactions while maintaining long-term electro-chemo-mechanical stability. Composite mixed- and triple-conducting structures may support superior hydrogenation and hydrogen oxidation reaction kinetics over time vs. single-phase electrodes. These architectures could offer task-sharing capabilities, resist poisoning of the full electrode surface, and/or limit catalyst agglomeration. We have tailored vertically aligned nanocomposite structures, exsolved nanocatalyst density, and coating basicity in geometrically well-defined thin-film electrodes prepared by pulsed laser deposition. Reaction kinetics were quantified using electrical and/or optical relaxation and impedance spectroscopy, demonstrating improved performance vs. the single-phase components. We also seek design principles for near-zero-strain electrodes that can accommodate the stoichiometry changes inherent in electrode operation without compromising mechanical integrity. Recent work, leveraging X-ray absorption spectroscopy, thermogravimetric analysis, diffraction, and dilatometry has demonstrated very low coefficients of chemical expansion in perovskites with tailored bond angles and charge distribution. |
