Promotion of PtIr and Pt catalytic activity towards ammonia electrooxidation through the modification of Zn

Junhua Jiang

Research output: Contribution to journalArticlepeer-review

Abstract

Zn is introduced into Pt and PtIr electrodes by applying potential cycles to their corresponding polycrystalline microdisc electrodes in a ZnCl2-containing ionic liquid bath. Scanning-electron microscopy and energy-dispersive X-ray microanalysis studies show that nanostructured PtIrZn and PtZn layers created on the microdisc electrodes contain approximately 5 wt% Zn. Cyclic voltammetric studies reveal that PtZn and PtIrZn are significantly more active towards electrochemical ammonia oxidation in alkaline media than virgin Pt and PtIr electrodes. The PtIrZn electrode demonstrates a low onset potential of 0.30 V vs RHE and a high exchange current density of 4.3 × 10− 8 A cm− 2, which is favorably comparable to state-of-the-art electrocatalyts for the same reaction. The catalytic activity promotion by the Zn modification may be related to the inhibition of the hydrogen electrochemistry. PtIrZn appears therefore to be a very promising anode catalyst for direct ammonia fuel cells and ammonia electrolysis.
Original languageEnglish (US)
Pages (from-to)52-55
Number of pages4
JournalElectrochemistry Communications
Volume75
DOIs
StatePublished - Feb 1 2017

Keywords

  • ISTC
  • Electrocatalytic activity
  • Zn modification
  • Ammonia electrooxidation
  • Platinum-iridium alloy
  • Platinum-iridium-zinc

ASJC Scopus subject areas

  • Electrochemistry

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