Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time

Catalyst dissolution is one of the key challenges in achieving long‐term performance in proton exchange membrane water electrolysis with low iridium loading. However, most of the dissolved catalyst remains in the catalyst‐coated membrane, inaccessible for operando quantification. While simpler aqueo...

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Main Authors: Nico C. Röttcher, Jiahua Zhou, Lukas Löttert, Karl J. J. Mayrhofer, Dominik Dworschak
Format: Article
Language:English
Published: Wiley-VCH 2025-07-01
Series:ChemElectroChem
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Online Access:https://doi.org/10.1002/celc.202500098
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author Nico C. Röttcher
Jiahua Zhou
Lukas Löttert
Karl J. J. Mayrhofer
Dominik Dworschak
author_facet Nico C. Röttcher
Jiahua Zhou
Lukas Löttert
Karl J. J. Mayrhofer
Dominik Dworschak
author_sort Nico C. Röttcher
collection DOAJ
description Catalyst dissolution is one of the key challenges in achieving long‐term performance in proton exchange membrane water electrolysis with low iridium loading. However, most of the dissolved catalyst remains in the catalyst‐coated membrane, inaccessible for operando quantification. While simpler aqueous model systems improve mechanistic understanding, dissolution rates are significantly overestimated compared to the device level. To bridge this gap, herein, an electrochemical half‐cell setup that mimics the anode catalyst layer environment to enable operation at relevant current densities (>1 A cm−1) is presented. Dissolved catalyst species transported through the porous transport layer or through the membrane are separately detected operando by coupling to inductively coupled plasma‐mass spectrometry. The results demonstrate a strong preference for the transport of dissolved iridium through the membrane (99.9%) and a decrease in catalyst stability by factor 10 at high current densities. Discrepancies with so far reported findings from full‐cell and half‐cell experiments highlight a lack of understanding of catalyst dissolution and the transportation of dissolved species in different systems. The presented method offers unique insights which will help to study and optimize catalyst dissolution by means of various manufacturing and operation parameters to ultimately improve the stability of catalyst layers for water electrolysis.
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institution Kabale University
issn 2196-0216
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series ChemElectroChem
spelling doaj-art-15b75a1f39fc4324b2a554264e797e752025-08-20T03:56:46ZengWiley-VCHChemElectroChem2196-02162025-07-011215n/an/a10.1002/celc.202500098Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real TimeNico C. Röttcher0Jiahua Zhou1Lukas Löttert2Karl J. J. Mayrhofer3Dominik Dworschak4Helmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IET‐2) Forschungszentrum Jülich Cauerstr. 1 91058 Erlangen GermanyHelmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IET‐2) Forschungszentrum Jülich Cauerstr. 1 91058 Erlangen GermanyHelmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IET‐2) Forschungszentrum Jülich Cauerstr. 1 91058 Erlangen GermanyHelmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IET‐2) Forschungszentrum Jülich Cauerstr. 1 91058 Erlangen GermanyHelmholtz Institute Erlangen‐Nürnberg for Renewable Energy (IET‐2) Forschungszentrum Jülich Cauerstr. 1 91058 Erlangen GermanyCatalyst dissolution is one of the key challenges in achieving long‐term performance in proton exchange membrane water electrolysis with low iridium loading. However, most of the dissolved catalyst remains in the catalyst‐coated membrane, inaccessible for operando quantification. While simpler aqueous model systems improve mechanistic understanding, dissolution rates are significantly overestimated compared to the device level. To bridge this gap, herein, an electrochemical half‐cell setup that mimics the anode catalyst layer environment to enable operation at relevant current densities (>1 A cm−1) is presented. Dissolved catalyst species transported through the porous transport layer or through the membrane are separately detected operando by coupling to inductively coupled plasma‐mass spectrometry. The results demonstrate a strong preference for the transport of dissolved iridium through the membrane (99.9%) and a decrease in catalyst stability by factor 10 at high current densities. Discrepancies with so far reported findings from full‐cell and half‐cell experiments highlight a lack of understanding of catalyst dissolution and the transportation of dissolved species in different systems. The presented method offers unique insights which will help to study and optimize catalyst dissolution by means of various manufacturing and operation parameters to ultimately improve the stability of catalyst layers for water electrolysis.https://doi.org/10.1002/celc.202500098high‐current operationhigh‐throughput screeningiridium dissolutiononline ICP‐MSwater electrolysis
spellingShingle Nico C. Röttcher
Jiahua Zhou
Lukas Löttert
Karl J. J. Mayrhofer
Dominik Dworschak
Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
ChemElectroChem
high‐current operation
high‐throughput screening
iridium dissolution
online ICP‐MS
water electrolysis
title Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
title_full Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
title_fullStr Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
title_full_unstemmed Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
title_short Tracing Iridium Dissolution Pathways in Proton Exchange Membrane Water Electrolyzers at Relevant Current Densities in Real Time
title_sort tracing iridium dissolution pathways in proton exchange membrane water electrolyzers at relevant current densities in real time
topic high‐current operation
high‐throughput screening
iridium dissolution
online ICP‐MS
water electrolysis
url https://doi.org/10.1002/celc.202500098
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