Acidic Hydrogen Evolution Electrocatalysis at High-Entropy Alloys Correlates with its Composition-Dependent Potential of Zero Charge

Moonjoo Kim; Emmanuel Batsa Tetteh; Olga A Krysiak; Alan Savan; Bin Xiao; Tobias Horst Piotrowiak; Corina Andronescu; Alfred Ludwig; Taek Dong Chung; Wolfgang Schuhmann

doi:10.1002/anie.202310069

Acidic Hydrogen Evolution Electrocatalysis at High-Entropy Alloys Correlates with its Composition-Dependent Potential of Zero Charge

Angew Chem Int Ed Engl. 2023 Sep 25;62(39):e202310069. doi: 10.1002/anie.202310069. Epub 2023 Aug 17.

Authors

Moonjoo Kim^{1

2}, Emmanuel Batsa Tetteh¹, Olga A Krysiak¹, Alan Savan³, Bin Xiao³, Tobias Horst Piotrowiak³, Corina Andronescu⁴, Alfred Ludwig^{3

5}, Taek Dong Chung^{2

6}, Wolfgang Schuhmann¹

Affiliations

¹ Analytical Chemistry-Center for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany.
² Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
³ Chair for Materials Discovery and Interfaces, Institute for Materials, Faculty of Mechanical Engineering, Ruhr University Bochum Universitätsstr. 150, D-44780, Bochum, Germany.
⁴ Technical Chemistry III and CENIDE Center for Nanointegration, Faculty of Chemistry, University of Duisburg-Essen, Carl-Benz-Straße 199, D-45141, Duisburg, Germany.
⁵ ZGH, Ruhr, University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany.
⁶ Advanced Institute of Convergence Technology, Suwon-si, Gyeonggi-do 16229, Republic of Korea.

PMID: 37537136
DOI: 10.1002/anie.202310069

Abstract

The vast possibilities in the elemental combinations of high-entropy alloys (HEAs) make it essential to discover activity descriptors for establishing rational electrocatalyst design principles. Despite the increasing attention on the potential of zero charge (PZC) of hydrogen evolution reaction (HER) electrocatalyst, neither the PZC of HEAs nor the impact of the PZC on the HER activity at HEAs has been described. Here, we use scanning electrochemical cell microscopy (SECCM) to determine the PZC and the HER activities of various elemental compositions of a Pt-Pd-Ru-Ir-Ag thin-film HEA materials library (HEA-ML) with high statistical reliability. Interestingly, the PZC of Pt-Pd-Ru-Ir-Ag is linearly correlated with its composition-weighted average work function. The HER current density in acidic media positively correlates with the PZC, which can be explained by the preconcentration of H⁺ in the electrical double layer at potentials negative of the PZC.

Keywords: High-Entropy Alloy; High-Throughput Analysis; Hydrogen Evolution Reaction; Potential of Zero Charge; Scanning Electrochemical Cell Microscopy (SECCM).

Abstract

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