2025-04-09 中国科学院(CAS)
<関連情報>
- https://english.cas.cn/newsroom/research_news/chem/202504/t20250407_909534.shtml
- https://www.cell.com/matter/abstract/S2590-2385(25)00139-0
白金系高エントロピー合金ナノオクタヘドラの超微細化によりメタノール酸化反応活性と耐久性が向上 Ultrafine Pt-based high-entropy alloy nanooctahedra deliver enhanced methanol oxidation reaction activity and durability
Chengyu Li∙ Peng Qin∙ Gongao Peng∙ Geoffrey I.N. Waterhouse∙ Lu Shang∙ Tierui Zhang
Matter Published:April 8, 2025
DOI:https://doi.org/10.1016/j.matt.2025.102096
Graphical abstract
Progress and potential
Pt-based nanooctahedra catalysts have been widely used in fuel cells due to the exposure of highly active (111) facets. However, reducing the size of nanooctahedra while maintaining their morphology is difficult; therefore, it limits the high utilization of Pt sites. Herein, we report a strategy to prepare ultrafine Pt-based nanooctahedra with an edge length of only 2.8 nm by constructing high-entropy alloys to reduce free energy. Furthermore, the synergistic effect of multiple elements favorably modulates the electronic structure of Pt, further enhancing the activity and stability of PtNiCuMoCoIr nanooctahedra for the methanol oxidation reaction (MOR). This study offers valuable insights and inspiration for the fabrication of nano-sized materials with ultrasmall, ultrafine, and ultrathin characteristics.
Highlights
- High-entropy effect can drive the reduction of nanoparticle size
- Ultrafine high-entropy alloy Pt-based nanooctahedra were synthesized
- Synergistic effect of multiple elements enhances catalytic performance
Summary
Pt-based nanooctahedra exposing highly active (111) facets demonstrate outstanding electrochemical activity in various types of fuel cells. However, simultaneously controlling the morphology, size, and electronic structure of such nanooctahedra is challenging. Herein, a high-entropy alloy (HEA) approach was adopted to reduce the size of the Pt-based nanooctahedra while also tuning the electronic structure. As a result, carbon-supported HEA PtNiCuMoCoIr nanooctahedra (PtNiCuMoCoIr/C, with an edge length of only 2.8 nm) exhibited a remarkable mass activity of 3.34 A mgPGM−1 for the methanol oxidation reaction (MOR) in acidic conditions, which was 2.2 and 7.3 times higher than ternary PtNiCu/C nanooctahedra and commercial Pt/C, respectively. Furthermore, PtNiCuMoCoIr/C exhibited excellent CO poisoning resistance with a mass activity loss of only 6.6% after a chronoamperometric test. The combination of ultrafine nanooctahedra and the selected HEA elements generated lattice strain and favorably tuned the electronic structure, which improved the MOR performance by enhancing the adsorption of ∗OH.
