Electrochemically decorated iridium electrodes with WS3−x toward improved oxygen evolution electrocatalyst stability in acidic electrolytes

Research output: Contribution to journalArticlepeer-review

Authors

  • Daniel Escalera-López
  • Kim D. Jensen
  • Neil Rees
  • María Escudero-Escribano

Colleges, School and Institutes

External organisations

  • University of Copenhagen

Abstract

Iridium-based oxides, currently the state-of-the-art oxygen evolution reaction (OER) electrocatalysts in acidic electrolytes, are cost-intensive materials which undergo significant corrosion under long-term OER operation. Thus, numerous researchers have devoted their efforts to mitigate iridium corrosion by decoration with corrosion-resistant metal oxides and/or supports to maximize OER catalyst durability whilst retaining high activity. Herein a one-step, facile electrochemical route to obtain improved IrOx thin film OER stability in acid by decorating with amorphous tungsten sulphide (WS3−x) upon electrochemical decomposition of a [WS4]2− aqueous precursor is proposed. The rationale behind applying such WS3−x decoration stems from the generation of a tungsten oxide phase, a well-known corrosion-resistant photoactive OER catalyst. The study demonstrates the viability of the proposed WS3−x decoration, allowing the tailoring of experimental parameters responsible for WS3−x nanoparticle size and surface coverage. OER stability tests coupled by ex situ SEM and XPS corroborate the beneficial effect of WS3−x decoration, yielding improved OER specific activity metrics along with minimized Ir surface roughening, a characteristic of electrodissolution. Iridium decoration with electrodeposited, corrosion-resistant oxides is consequently shown to be a promising route to maximize OER stabilities.

Bibliographic note

Funding Information: D.E.L. and N.V.R. would like to thank the EPSRC for support through funding for the Centre for Doctoral Training in Fuel Cells and their Fuels (EP/G037116/1 and EP/L015749/1). K.D.J. and M.E.‐E. would like to thank the Danish Council for Independent Research (DFF) for support though grant 9041‐00224B. M.E.‐E. gratefully acknowledges support from the Villum Foundation under the Villum Young Investigator Programme (project number 19142). The authors would also like to thank Dr. Francisco Javier del Campo and Dr. Joaquima López García at the IMB‐CNM (CSIC) for the preparation of the Si/Cr/Ir electrodes used in this work, and Dr. Mark Isaacs at the HarwellXPS (Rutherford Appleton Labs, National EPSRC XPS National Facility) for support during X‐ray photoelectron spectroscopy measurements. Publisher Copyright: © 2021 Wiley-VCH GmbH

Details

Original languageEnglish
JournalAdvanced Sustainable Systems
Early online date1 Mar 2021
Publication statusE-pub ahead of print - 1 Mar 2021

Keywords

  • electrocatalysis, electrochemical deposition, iridium, oxygen evolution reaction, stability, transition metal oxide, water electrolysis

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