In Situ TEM Reveals Direct One-Step Reduction of van der Waals Crystal MoO<sub>3</sub> to Mo
Molybdenum oxides (MOs) exhibit rich polymorphism and tunable properties, yet their phase transformation pathways are poorly understood. Here, we employ in situ environmental transmission electron microscopy (TEM) to reveal a direct reduction of MoO<sub>3</sub> to metallic Mo, bypassing known intermediate phases such as MoO<sub>2</sub> and Mo<sub>4</sub>O<sub>11</sub>. Surface nucleation begins at approximately 800 °C and is completed at 900 °C. Molecular dynamics (MD) and density functional theory (DFT) calculations attribute this unexpected transformation to the van der Waals (vdW) layered structure of MoO<sub>3</sub>, which lowers both the oxygen binding energy and the Gibbs free energy (ΔG) for oxygen desorption under high-vacuum and high-temperature conditions. Preferential oxygen removal from the weakly bonded vdW layers facilitates a rapid reduction to the metallic phase. These findings uncover a nonclassical reduction mechanism and provide a pathway for the rational design of MOs with controllable phases and properties.
Authors
- T. D. Xu (ORCID: https://orcid.org/0000-0002-1536-4734)
- Wei Tu (ORCID: https://orcid.org/0000-0002-0255-4037)
- Xuan Song (ORCID: https://orcid.org/0000-0002-2237-4236)
- Fan Zhang (ORCID: https://orcid.org/0000-0001-5180-9895)
- Xianhu Sun (ORCID: https://orcid.org/0000-0002-9509-2950)
- Jin Lu (ORCID: https://orcid.org/0000-0001-6219-6166)
- An Bai
- Jianyu Huang (ORCID: https://orcid.org/0000-0002-8424-5368)
- Zhen Zeng
- Yao Yang (ORCID: https://orcid.org/0000-0002-2896-9046)
Institutions
- Westlake University (CN)
- Yanshan University (CN)
- Binzhou People's Hospital (CN)
- Science & Technology Park (Czechia) (CZ)
- Weifang University of Science and Technology (CN)
- Nano Energy (South Africa) (ZA)
- University of Chinese Academy of Sciences (CN)
- State Key Laboratory of Metastable Materials Science and Technology
- Xiangtan University (CN)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-09-04
- DOI
- https://doi.org/10.1021/acs.nanolett.5c03929
- Citations
- 2
- Primary Topic
- Transition Metal Oxide Nanomaterials
- Type
- article
- Field-Weighted Citation Impact
- 1.21
Funders
- National Natural Science Foundation of China
- Natural Science Foundation of Hebei Province
- University of Chinese Academy of Sciences
- National Key Research and Development Program of China
- Natural Science Foundation of Zhejiang Province