白金ナノ粒子の3次元原子構造解析に成功 ―不均一触媒における発現機構の理解と新たな設計指針の構築―

2026-02-27 東京大学

東京大学大学院理学系研究科などの国際研究チームは、約129億年前(赤方偏移z=6)の星形成銀河をアルマ望遠鏡で観測し、フッ素(フッ化水素HF)の吸収線を探索したが有意検出は得られず、宇宙初期におけるフッ素存在量の最も厳しい上限値を与えた。対象は重力レンズで増光した銀河G09.83808で、性質を反映した理論モデルと比較。もしウォルフ・ライエ星(WR星)が主要起源なら検出されるはずだが非検出だったため、宇宙初期でWR星がフッ素を大量供給したとする従来説と整合しない可能性を示した。今後はJWST観測も組み合わせ起源解明を進める。成果はThe Astrophysical Journal Letters掲載。

白金ナノ粒子の3次元原子構造解析に成功 ―不均一触媒における発現機構の理解と新たな設計指針の構築―
原子分解能電子顕微鏡像の統計的解析に基づく3次元原子構造および電荷密度分布

<関連情報>

SrTiO3 (001)上におけるPtナノ粒子の原位加熱時の3D動的構造:原子分解能ADF STEMイメージング 3D dynamic structure of a Pt nanoparticle on SrTiO3 (001) during in-situ heating atomic-resolution ADF STEM imaging

Ryo Ishikawa,Rikuto Kubota,Kazuaki Kawahara,Toshihiro Futazuka,Yuichi Ikuhara & Naoya Shibata
Nature Communications  Published:27 February 2026
DOI:https://doi.org/10.1038/s41467-026-69767-5

Abstract

Noble metal nanoparticles supported on semiconducting substrates have long been used in heterogeneous catalysis. A central objective in this field is to identify the active sites for catalysis, which requires precise determination of the 3D atomic structure of nanoparticles on substrates. Furthermore, it has widely accepted that catalytic active sites undergo dynamic structural changes under reaction conditions. However, direct observation of such 3D dynamic structures at the atomic scale, particularly under elevated temperatures and reducing environments, remains a challenge. Here, we present the 3D atomic structure of an epitaxially grown platinum nanoparticle, consisting of 263 Pt atomic sites, supported on an atomically flat SrTiO3 (001) surface, using single-projection atomic-resolution scanning transmission electron microscopy (STEM) combined with quantitative statistical analysis. In-situ heating experiments under reduced atmosphere reveal that the Pt atoms with lower coordination numbers are mobile within the second-nearest-neighbor atomic sites, and we describe the 3D dynamic atomic structure of the Pt nanoparticle by the distribution of partial occupation of Pt atoms. Furthermore, we perform density functional theory calculations based on the experimentally reconstructed 3D atomic structure and find that excess negative charges accumulate at the lower CN atomic sites, which likely serve as catalytically active sites.

1701物理及び化学
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