AgSn intermetallics as highly selective and active oxygen reduction electrocatalysts in membraneless alkaline fuel cells

Qiao Wang, Fuyi Chen, Yaxing Liu, Tesfaye Tadesse Gebremariam, Junpeng Wang, Liang An, Roy L. Johnston

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

The Ag4Sn and Ag3Sn intermetallics are successfully synthesized by combining electrochemical deposition and dealloying methods. The Ag4Sn and Ag3Sn possess a half-wave potential of 0.810 mV and 0.790 mV respectively for the oxygen reduction reaction in alkaline media, which are comparable to the commercial Pt/C (0.837 mV). In term of the durability, the Ag4Sn retains a half-wave potential of 0.775 mV after 5000 potential cycles, which is superior to Pt/C of 0.784 mV. The better catalytic activity and durability are mainly attributed to the ensemble effect and strong chemical bond in the AgSn ordered intermetallic structure. The catalytic activity is hardly influenced by methanol or ethanol in alkaline media with alcohol concentrations up to 1.0 M. Therefore, a membraneless alkaline zinc-air battery and direct alcohol fuel cell can operate with Ag4Sn and Ag3Sn intermetallics as the cathode catalysts, which allow the anode fuel to freely enter the cathode. A high power density is delivered by the membraneless alkaline fuel cells with zinc, methanol or ethanol as anode fuels. The excellent alcohol-tolerance is beneficial to the oxygen reduction reaction of alkaline fuel cells and makes the AgSn intermetallics a promising candidate to replace Pt-based electrocatalysts for oxygen reduction reaction.

Original languageEnglish
Pages (from-to)106-117
Number of pages12
JournalJournal of Power Sources
Volume404
DOIs
Publication statusPublished - 15 Nov 2018

Keywords

  • Intermetallic
  • Membraneless alkaline fuel cells
  • Oxygen reduction reaction
  • Silver
  • Tin

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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