ETEM observation of Pt/C electrode catalysts in a moisturized cathode atmosphere

K. Yoshida, X. Zhang, N. Tanaka, E. D. Boyes, P. L. Gai

Research output: Contribution to journalConference article

1 Citation (Scopus)

Abstract

There have been reports of challenges in designing platinum carbon (Pt/C) electrode catalysts for PEMFC. Pt/C electrode catalysts deactivate much faster on the cathode (in moisturized O2) than on the anode (in H 2). To understand influences of moisture and oxygen on the deactivation of the Pt/C catalysts in proton-exchange-membrane fuel cells (PEMFCs), spherical-aberration-corrected environmental transmission electron microscopy (AC-ETEM) was applied with a high-speed CCD camera. Structural changes of the Pt/C electrode catalysts were dynamically recorded in moisturized nitrogen, oxygen and hydrogen. The mass spectrometry confirmed the moisture content (between 5 to 30 %) of nitrogen driving gas through a humidifier. Coalescence of platinum nanoparticles (D 3.24 nm) was carefully evaluated in pure N2 and moisturized N2 atmosphere. The Pt/C showed considerable structural weakness in a moisturized N2 atmosphere. Comparable results obtained by AC-ETEM in different gas atmospheres also suggested ways to improve the oxygen reduction reaction (ORR). In this paper, the deactivation process due to moisture (hydroxylation) of carbon supports is discussed using for comparison the movement of platinum nanoparticles measured in moisturized nitrogen and pure nitrogen atmospheres.

Original languageEnglish
Article number012007
JournalJournal of Physics: Conference Series
Volume522
Issue number1
DOIs
Publication statusPublished - 2014 Jan 1
Externally publishedYes
EventElectron Microscopy and Analysis Group Conference 2013, EMAG 2013 - York, United Kingdom
Duration: 2013 Sep 32013 Sep 6

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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