Jiayue Wang

All Publications

• Fermi Level Equilibration and Charge Transfer at the Exsolved Metal-Oxide Interface. Journal of the American Chemical Society Wang, J., Yang, J., Wardini, J. L., Waluyo, I., Hunt, A., Crumlin, E. J., Fairley, N., Bowman, W. J., Hwang, H. Y., Yildiz, B. 2025

  Abstract

  Exsolution is a promising approach for fabricating oxide-supported metal nanocatalysts through redox-driven metal precipitation. A defining feature of exsolved nanocatalysts is their anchored metal-oxide interface, which exhibits exceptional structural stability in (electro)catalysis. However, the electronic interactions at this unique interface remain unclear, despite their known impact on catalytic performance. In this study, we confirm charge transfer between the host oxide and the exsolved metal by demonstrating a two-stage Fermi level (EF) evolution on SrTi0.65Fe0.35O3-δ (STF) during metallic iron (Fe0) exsolution. Combining ambient pressure X-ray photoelectron spectroscopy with theoretical analysis, we show that EF initially rises due to electron doping from oxygen vacancy formation in STF. Subsequently, upon Fe0 precipitation, EF stabilizes and becomes insensitive to further oxygen release in STF, driven by EF equilibration and charge transfer between STF and the exsolved Fe0. These findings highlight the importance of considering electronic metal-support interactions when optimizing exsolved nanocatalysts.

  View details for DOI 10.1021/jacs.4c14695

  View details for PubMedID 39818799

• Molecular H2as the Reducing Agent in Low-Temperature Oxide Reduction Using Calcium Hydride. Journal of the American Chemical Society Wang, J., Yu, Y., Abdelkawy, A., Li, J., Li, J., Yang, J., Ko, E. K., Lee, Y., Thampy, V., Cui, Y., Todorova, M., Neugebauer, J., Hwang, H. Y. 2025

  Abstract

  Low-temperature synthesis is crucial for advancing sustainable manufacturing and accessing novel metastable phases. Metal hydrides have shown great potential in facilitating the reduction of oxides at low temperatures, yet the underlying mechanism─whether driven by H-, H2, or atomic H─remains unclear. In this study, we employ in situ electrical transport measurements and first-principles calculations to investigate the CaH2-driven reduction kinetics in epitaxial alpha-Fe2O3 thin films. Intriguingly, samples in direct contact with or separated from CaH2 powders exhibit similar apparent activation energies for H2 reduction, although direct contact significantly increases the reduction rate. These findings indicate that molecular H2 is the dominant reducing species in the low-temperature reduction of oxides using CaH2, with a key aspect of the hydrides' superior reducing power attributed to their ability to eliminate residual moisture. This work underscores the critical role of moisture control in enabling effective low-temperature oxide reduction for advanced material synthesis.

  View details for DOI 10.1021/jacs.4c17825

  View details for PubMedID 39807810

• Recommended strategies for quantifying oxygen vacancies with X-ray photoelectron spectroscopy JOURNAL OF THE EUROPEAN CERAMIC SOCIETY Wang, J., Mueller, D. N., Crumlin, E. J. 2024; 44 (15)

  View details for DOI 10.1016/j.jeurceramsoc.2024.116709

  View details for Web of Science ID 001275754400001