About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fundamentals of Sustainable Metallurgy and Materials Science
|
| Presentation Title |
Understanding Early Stages of Low-temperature Hydrogen-driven Direct Co-reduction of Fe-Ni Mixed Oxide Thin Films at the Near Atomic Scale |
| Author(s) |
Emmanuel Uwayezu, Shaolou Wei, Yujiao Li, Johannes D. Bartl, Dierk Raabe, Alfred Ludwig |
| On-Site Speaker (Planned) |
Emmanuel Uwayezu |
| Abstract Scope |
Kinetic understanding of the hydrogen co-reduction of multicomponent/multi-phase oxides is of interest for enhancing the sustainability of alloy production and transition to a hydrogen-based economy. In this study, the early stages of the hydrogen direct reduction of oxide thin films are investigated using a Fe50Ni50Ox thin film consisting of NiFe2O4 and NiO phases as a case study. The film is reduced in a flow of pure H2 at 280°C for different times, and using different characterisation techniques including atom probe tomography, it is revealed that the film’s low-temperature reduction is nucleation-limited and that the early-stages of the reduction involves phase separation into a Ni-rich FexNiy metallic phase and a transformed remaining oxide (magnetite, Fe3O4). Further reduction induces magnetite reduction and alloying into a nearly equiatomic FeNi alloy. The low-temperature reduction and alloying are facilitated by synergetic effects from the film’s nanostructure, and Ni autocatalytic effects through alloying and hydrogen spillover. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Sustainability, Thin Films and Interfaces, Characterization |