| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials for Sustainable Hydrogen Energy
|
| Presentation Title |
Size and Shape Dependence of Hydrogen-Induced Phase Transformation and Sorption Hysteresis in Palladium Nanoparticles |
| Author(s) |
Xingsheng Sun |
| On-Site Speaker (Planned) |
Xingsheng Sun |
| Abstract Scope |
We establish a computational framework to explore the atomic configuration of a metal-hydrogen system when in equilibrium with a H environment. This approach combines Diffusive Molecular Dynamics with an iteration strategy, aiming to minimize the system's free energy and ensure uniform chemical potential across the system. Applying this framework, we investigate H chemical potential-composition isotherms during the hydrogenation and dehydrogenation of palladium nanoparticles, ranging in size from 3.9 nm to 15.6 nm and featuring various shapes including cube, rhombic dodecahedron, octahedron, and sphere. Our findings reveal an abrupt phase transformation in all examined particles during both H loading and unloading processes, accompanied by a distinct hysteresis gap between absorption and desorption chemical potentials. We will show the effects of size and shape on the chemical potentials at phase transitions. These effects are elucidated by statistics of atomic volumetric strains resulting from specific facet orientations and inhomogeneous H distributions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Modeling and Simulation, Other |