Stability of high-entropy alloys under electrocatalytic conditions

Attila Kormányos; Qi Dong; Bin Xiao; Tangyuan Li; Alan Savan; Ken Jenewein; Tatiana Priamushko; Andreas Körner; Thomas Böhm; Andreas Hutzler; Liangbing Hu; Alfred Ludwig; Serhiy Cherevko

doi:10.1016/j.isci.2023.107775

Stability of high-entropy alloys under electrocatalytic conditions

iScience. 2023 Aug 30;26(10):107775. doi: 10.1016/j.isci.2023.107775. eCollection 2023 Oct 20.

Authors

Attila Kormányos^{1

2}, Qi Dong³, Bin Xiao⁴, Tangyuan Li³, Alan Savan⁴, Ken Jenewein^{1

5}, Tatiana Priamushko¹, Andreas Körner¹, Thomas Böhm¹, Andreas Hutzler¹, Liangbing Hu^{3

6}, Alfred Ludwig⁴, Serhiy Cherevko¹

Affiliations

¹ Forschungszentrum Jülich GmbH, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Cauerstraße 1, 91058 Erlangen, Germany.
² Department of Physical Chemistry and Materials Science, University of Szeged, Aradi sq. 1, 6720 Szeged, Hungary.
³ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, United States.
⁴ Materials Discovery and Interfaces, Institute for Materials, Ruhr-Universität Bochum, 44801 Bochum, Germany.
⁵ Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
⁶ Center for Materials Innovation, University of Maryland, College Park, MD 20742, United States.

Abstract

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.

Keywords: Electrochemical materials science; Interfacial electrochemistry; Nanoelectrochemistry.