Javed Hassan, Kolmeijer Kees, Deka Nipon, van Spronsen Matthijs A, van Huis Marijn A, Mohandas Sandhya Athira Lekshmi, Khalakhan Ivan, Mom Rik V
Leiden Institute of Chemistry, Leiden University, PO Box 9502, Leiden 2300 RA, The Netherlands.
Diamond Light Source Ltd., Harwell Science and Innovation Campus, Chilton, Didcot OX11 0DE, U.K.
ACS Catal. 2025 Jul 16;15(15):12994-13002. doi: 10.1021/acscatal.5c02601. eCollection 2025 Aug 1.
The distribution of elements within alloy nanoparticles is a critical parameter for their electrocatalytic performance. Here, we use the case of a PtNi alloy to show that this elemental distribution can dynamically respond to the applied potential, leading to strongly potential-dependent catalytic properties. Starting from the PtNi core and Pt shell structure that forms in acid electrolyte due to Ni leaching, our electrochemical X-ray photoelectron spectroscopy measurements show that the Ni atoms can be reversibly moved between the core of the particles and the near-surface region using the applied potential. Through potential jump measurements, we show that this Ni migration modulates the hydrogen evolution reaction activity of the particles by over 30%. These observations highlight the potential of incorporating in situ restructuring of alloys as the final step in electrocatalyst design.
合金纳米颗粒中元素的分布是决定其电催化性能的关键参数。在此，我们以铂镍合金为例，证明这种元素分布能够对施加的电势产生动态响应，从而导致催化性能强烈依赖于电势。从在酸性电解质中由于镍浸出而形成的铂镍核壳结构出发，我们的电化学X射线光电子能谱测量表明，利用施加的电势，镍原子能够在颗粒的核心与近表面区域之间可逆移动。通过电势阶跃测量，我们表明这种镍迁移使颗粒的析氢反应活性改变超过30%。这些观察结果突出了将合金的原位重构作为电催化剂设计最后一步的潜力。
