Hydrogen egress from palladium surfaces: A microelectrode-based investigation

S. Zhang, K. Nairn, M. Musameh, S. Thomas

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)

Abstract

Atomic hydrogen could participate in multiple electrochemical reactions during egress from Palladium (Pd) into aqueous environments. Possible reactions include hydrogen recombination to form H2, the oxygen reduction reaction (ORR) and “hydrogen ionisation” to form H+. Here, bulk measurements and microelectrode-based methods were used to mechanistically investigate such reactions occurring during hydrogen egress from Pd. Significant ORR was detected on hydrogen-charged Pd (Pd-H) surfaces, when using a Platinum (Pt) microelectrode (ME) in the redox competition mode. However, minor hydrogen recombination was also detected while using the Pt ME in the sample generation-tip collection (SG-TC) mode. Hydrogen ionisation is observed to occur when Pd (H) is anodically polarised. These reactions can all be linked to the highly negative equilibrium potential of the atomic H/H+ redox couple. Atomic hydrogen being a strong reducing agent thus tends to efficiently reduce various oxidants in solution resulting in different products, under varying conditions.

Original languageEnglish
Article number117690
Number of pages11
JournalJournal of Electroanalytical Chemistry
Volume946
DOIs
Publication statusPublished - 1 Oct 2023

Keywords

  • Hydrogen
  • Hydrogen detection
  • Hydrogen embrittlement
  • Hydrogen evolution reaction
  • Ion-selective electrode
  • Oxygen reduction
  • Palladium hydride
  • Scanning electrochemical microscopy

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