Kormányos Attila, Dong Qi, Xiao Bin, Li Tangyuan, Savan Alan, Jenewein Ken, Priamushko Tatiana, Körner Andreas, Böhm Thomas, Hutzler Andreas, Hu Liangbing, Ludwig Alfred, Cherevko Serhiy
Forschungszentrum Jülich GmbH, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Cauerstraße 1, 91058 Erlangen, Germany.
Department of Physical Chemistry and Materials Science, University of Szeged, Aradi sq. 1, 6720 Szeged, Hungary.
iScience. 2023 Aug 30;26(10):107775. doi: 10.1016/j.isci.2023.107775. eCollection 2023 Oct 20.
High-entropy alloys are claimed to possess superior stability due to thermodynamic contributions. However, this statement mostly lies on a hypothetical basis. In this study, we use on-line inductively coupled plasma mass spectrometer to investigate the dissolution of five representative electrocatalysts in acidic and alkaline media and a wide potential window targeting the most important applications. To address both model and applied systems, we synthesized thin films and carbon-supported nanoparticles ranging from an elemental (Pt) sample to binary (PtRu), ternary (PtRuIr), quaternary (PtRuIrRh), and quinary (PtRuIrRhPd) alloy samples. For certain metals in the high-entropy alloy under alkaline conditions, lower dissolution was observed. Still, the improvement was not striking and can be rather explained by the lowered concentration of elements in the multinary alloys instead of the synergistic effects of thermodynamics. We postulate that this is because of dissolution kinetic effects, which are always present under electrocatalytic conditions, overcompensating thermodynamic contributions.
由于热力学贡献，高熵合金据称具有卓越的稳定性。然而，这一说法大多基于假设。在本研究中，我们使用在线电感耦合等离子体质谱仪，针对最重要的应用，在酸性和碱性介质以及宽电位窗口中研究了五种代表性电催化剂的溶解情况。为了兼顾模型系统和应用系统，我们合成了薄膜以及从元素（Pt）样品到二元（PtRu）、三元（PtRuIr）、四元（PtRuIrRh）和五元（PtRuIrRhPd）合金样品的碳载纳米颗粒。在碱性条件下，对于高熵合金中的某些金属，观察到较低的溶解情况。不过，这种改善并不显著，并且更可能是由多元合金中元素浓度降低而非热力学协同效应来解释。我们推测这是由于溶解动力学效应，其在电催化条件下始终存在，从而过度补偿了热力学贡献。
