2025-11-18 パシフィック・ノースウェスト国立研究所 (PNNL)
Specially synthesized assemblies of palladium particles with grain boundaries had significantly faster hydrogen insertion than similar-sized isolated palladium nanoparticles.(Image by Hyoju Park | Pacific Northwest National Laboratory)
＜関連情報＞
- https://www.pnnl.gov/publications/grain-boundaries-accelerate-hydrogen-insertion-palladium-nanostructures
- https://pubs.acs.org/doi/10.1021/acs.nanolett.5c03431
Σ3(111)粒界はパラジウムナノ構造への水素挿入を促進する Σ3(111) Grain Boundaries Accelerate Hydrogen Insertion into Palladium Nanostructures
K. A. U. Madhushani,Hyoju Park,Hua Zhou,Diptangshu Datta Mal,Bingxin Yang,Qin Pang,Dongsheng Li,Peter V. Sushko,and Long Luo
Nano Letters Published: October 10, 2025
DOI:https://doi.org/10.1021/acs.nanolett.5c03431
Abstract
Grain boundaries (GBs) are frequently implicated as key defect structures facilitating metal hydride formation, yet their specific role remains poorly understood due to their structural complexity. Here, we investigate hydrogen insertion in Pd nanostructures enriched with well-defined Σ3(111) GBs (PdGB) synthesized via electrolysis-driven nanoparticle assembly. In situ synchrotron X-ray diffraction reveals that PdGB exhibits dramatically accelerated hydriding and dehydriding kinetics compared with ligand-free and ligand-capped Pd nanoparticles with similar crystallite sizes. Strain mapping using environmental transmission electron microscopy shows that strain is highly localized at GBs and intensifies upon hydrogen exposure, indicating preferential hydrogen insertion along GB sites. Density functional theory calculations provide mechanistic insight supporting these findings, showing that hydrogen insertion near Σ3(111) GBs is energetically more favorable and that tensile strain lowers insertion barriers. These results provide atomic-level insights into the role of GBs in hydride formation and suggest new design strategies for GB-engineered Pd-based functional materials.
