Affordable Access

Access to the full text

Hydrogen Treatment as Potential Protection of Electrodeposited Pt, Au, and Pt/Au Oxygen Reduction Catalysts on TiOx

Authors
  • Proch, Sebastian1, 2
  • Yoshino, Shuhei1
  • Kamitaka, Yuji1
  • Takahashi, Naoko1
  • Seki, Juntaro1
  • Kosaka, Satoru1
  • Kodama, Kensaku1
  • Morimoto, Yu1
  • 1 Toyota Central R&D Labs., Inc., 41-1, Yokomichi, Nagakute, Aichi, 480-1192, Japan , Nagakute (Japan)
  • 2 Sandvik Materials Technology, Sandviken, 81181, Sweden , Sandviken (Sweden)
Type
Published Article
Journal
Electrocatalysis
Publisher
Springer US
Publication Date
Sep 12, 2018
Volume
10
Issue
1
Pages
1–16
Identifiers
DOI: 10.1007/s12678-018-0489-8
Source
Springer Nature
Keywords
License
Yellow

Abstract

Methods of protecting Pt(-alloy) particles against dissolution during fuel cell operation have recently gathered attention. Titania as a promising Pt catalyst support has its own built-in protection mechanism, called strong metal-support interaction (SMSI), which leads to encapsulation of metal particles. A high-coverage Pt particle film (approximated layer) with high oxygen reduction activity on the native oxide of metallic titanium has been heat treated in a hydrogen atmosphere. This treatment gave rise to its protection with a thin TiOx layer while Pt particle sintering or the destruction of the Pt structure was avoided. This unique behavior might originate from the structure of this approximate layer; i.e., contiguous patches of TiOx allow fast SMSI/encapsulation of the whole Pt structure before massive sintering or destruction can take place. Although the film was found to be covered by a 5.0 ± 0.1-nm TiOx overlayer, oxygen reduction with a mass activity of 26 ± 4 A gPt−1 could still be observed. Graphical AbstractOnce layer-like, always layer-like: Heat treatment of a very closely spaced Pt particle film leads to retention of this structure and formation of a TiOx overlayer by the strong metal-support interaction. In contrast, sparsely distributed Pt particles sinter under those conditions. This difference in behavior also has consequences on the oxygen reduction activity.

Report this publication

Statistics

Seen <100 times