Same-View Nano-XAFS/STEM-EDS Imagings of Pt Chemical Species in Pt/C Cathode Catalyst Layers of a Polymer Electrolyte Fuel Cell.
We have made the first success in the same-view imagings of 2D nano-XAFS and TEM/STEM-EDS under a humid N2 atmosphere for Pt/C cathode catalyst layers in membrane electrode assemblies (MEAs) of polymer electrolyte fuel cells (PEFCs) with Nafion membrane to examine the degradation of Pt/C cathodes by anode gas exchange cycles (start-up/shut-down simulations of PEFC vehicles). The same-view imaging under the humid N2 atmosphere provided unprecedented spatial information on the distribution of Pt nanoparticles and oxidation states in the Pt/C cathode catalyst layer as well as Nafion ionomer-filled nanoholes of carbon support in the wet MEA, which evidence the origin of the formation of Pt oxidation species and isolated Pt nanoparticles in the nanohole areas of the cathode layer with different Pt/ionomer ratios, relevant to the degradation of PEFC catalysts.
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Shinobu
S
Takao
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Oki
O
Sekizawa
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Gabor
G
Samjeské
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Shin-ichi
S
Nagamatsu
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Takuma
T
Kaneko
‡Department of Mathematical and Material Sciences, Faculty of Integrated Arts and Sciences, The University of Tokushima, Minamijosanjima, Tokushima 770-8502, Japan.
Takashi
T
Yamamoto
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Kotaro
K
Higashi
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Kensaku
K
Nagasawa
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.|§Japan Synchrotron Radiation Research Institute, Spring-8, Sayo, Hyogo 679-5198, Japan.
Tomoya
T
Uruga
†Innovation Research Center for Fuel Cells, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.|∥Department of Engineering Science, Graduate School of Information Engineering Science, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo 182-8585, Japan.
Yasuhiro
Y
Iwasawa
Pt/C fuel-cell catalyst; TEM/STEM-EDS; mapping of Pt species degradation; nano-XAFS mapping; same-view nanoimaging