【公開日：2025.06.10】【最終更新日：2025.05.09】

課題データ / Project Data

課題番号 / Project Issue Number

24UT0088

利用課題名 / Title

Design and preparation of catalysts for acidic water oxidation

利用した実施機関 / Support Institute

東京大学 / Tokyo Univ.

機関外・機関内の利用 / External or Internal Use

内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)

技術領域 / Technology Area

【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-

【重要技術領域 / Important Technology Area】（主 / Main）次世代ナノスケールマテリアル/Next-generation nanoscale materials（副 / Sub）-

キーワード / Keywords

Ce and W co-doped RuO2 nano-micro spheres,X線回折/ X-ray diffraction,ナノ粒子/ Nanoparticles,電子顕微鏡/ Electronic microscope,電子分光/ Electron spectroscopy

利用者と利用形態 / User and Support Type

利用者名（課題申請者）/ User Name (Project Applicant)

Liu Hongzhi

所属名 / Affiliation

東京大学大学院工学系研究科機械工学専攻

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

利用形態 / Support Type

（主 / Main）機器利用/Equipment Utilization（副 / Sub）,技術補助/Technical Assistance

利用した主な設備 / Equipment Used in This Project

UT-005：原子分解能元素マッピング構造解析装置
UT-006：ハイスループット電子顕微鏡
UT-203：粉末X線回折装置
UT-308：多機能走査型X線光電子分光分析装置(XPS)with AES

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

To detect the crystal structure and elements distribution of RuO2 crystals.Because there are dopants (W and Ce elements) in RuO2 crystals, instead of pure RuO2 crystals. So I applied to characterize the compositions by TEM and EDS mapping, which helped to determine the percentages of dopants.Additionally, the dopants have effects on the crystalline distortion. I used XRD to see the shift of diffraction peaks.Finally, the oxygen evolution reaction mechanisms of RuO2-based catalysts are highly dependent on the electronic structures of Ru and Ru-O bonding covalency, so I measured XPS to analyzed the electronic structures of d orbit in RuO2 catalysts to see how W and Ce dopants affect the electronic structures of Ru.

実験 / Experimental

XRD  (SmartLab (3kW))measurements, showing that the (110) facets are the main facets of RuO2, which is typically responsible for the oxygen evolution reaction.TEM and EDS (JEM-2800,JEM-ARM200F Thermal FE(STEM SDD))measurements, showing that W and Ce are uniformly distributed in the RuO2 spheres, with a doping content of 25% and 2%,  respectively.XPS( VersaProbeⅢ) measurements, showing that W and Ce exist significant electronic interaction with Ru, regulating the electronic structure of Ru and Ru-O covalency.

結果と考察 / Results and Discussion

X-ray diffraction (XRD) measurements reveal that the (110) facets are the dominant crystal facets of RuO2, which are primarily responsible for catalyzing the oxygen evolution reaction (OER). In addition, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) measurements confirm that tungsten (W) and cerium (Ce) are uniformly incorporated within the RuO2 spheres, with doping concentrations of 25% for W and 2% for Ce, respectively. These doping elements play a crucial role in altering the properties of the RuO2 catalyst. Furthermore, X-ray photoelectron spectroscopy (XPS) measurements indicate that both W and Ce exhibit significant electronic interactions with the Ru atoms, which modulate the electronic structure of Ru and affect the Ru-O covalency. This interplay between the dopants and the RuO2 matrix is vital for optimizing the catalytic pathway of the oxygen evolution reaction. And the sequential electrochemical measurements indicates that the W dopants reduce the Ru-O covalency to suppress the reactivity of lattice oxygen, and this suppressed reactivity can be recovered after Ce doping.

図・表・数式 / Figures, Tables and Equations

Fig a. The SAED pattern of RuO2 sphere.Fig b. The atomic distribution of RuO2 sphere.Fig c. The RuO2 sphere and corresponding EDS map.

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

1. Yao, N.; Jia, H. N.; Zhu, J.; Shi, Z. P.; Cong, H. J.; Ge, J. J.; Luo, W. Atomically dispersed Ru oxide catalyst with lattice oxygen participation for efficient acidic water oxidation. Chem 2023, 9, 1882−1896.2. Liu, H.; Zhang, Z.; Fang, J. J.; Li, M. X.; Sendeku, M. G.; Wang, X.; Wu, H. Y.; Li, Y. P.; Ge, J. J.; Zhuang, Z. B.; Zhou, D. J.; Kuang, Y.; Sun X. M. Eliminating over-oxidation of ruthenium oxides by niobium for highly stable electrocatalytic oxygen evolution in acidic media. Joule 2023, 7, 558−573.

成果発表・成果利用 / Publication and Patents

論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)

口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.

特許 / Patents

特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件