Open AccessSurface-Modified Titanium Fibers as Durable Carbon-Free Platinum Catalyst Supports for Polymer Electrolyte Fuel Cells
Author(s) -
Daiki Kawachino,
Masahiro Yasutake,
Zhiyun Noda,
Junko Matsuda,
Stephen Matthew Lyth,
Akari Hayashi,
Kazunari Sasaki
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab9cd4
Subject(s) - materials science , electrolyte , titanium , electrode , chemical engineering , current collector , platinum , catalysis , gaseous diffusion , polymer , catalyst support , composite material , metal , metallurgy , chemistry , organic chemistry , engineering
Carbon-based electrodes in polymer electrolyte fuel cells (PEFCs) are prone to corrosion. Therefore, alternative “carbon-free” materials are required. Here, the use of a catalyst-coated porous metal support is proposed as a gas diffusion electrode. As a proof-of-concept, commercially available porous titanium sheets comprising sintered titanium fibers are chemically etched with NaOH, followed by heat treatment. This results in the formation of oxidized titanium nanostructures (such as nanosheets and nanotubes) at the surface. Subsequently, platinum decoration is performed via arc plasma deposition (APD). This porous composite structure is then attached to the membrane, and used as the gas diffusion electrode for PEFC membrane electrode assemblies (MEAs). This concept integrates the catalyst, catalyst support, gas diffusion layer, and current collector in a single structure, cutting down on the number of cell components and reducing total device thickness. The carbon-free nature of this integrated gas diffusion electrode is demonstrated to successfully avoid carbon corrosion during start-stop potential cycling over 60,000 potential cycles. However, further improvements in initial electrochemical activity are still required.