Microstructural observation of fuel cell catalyst inks by Cryo-SEM and Cryo-TEM.
In order to improve the electricity generation performance of fuel cell electric vehicles, it is necessary to optimize the microstructure of the catalyst layer of a polymer electrolyte fuel cell. The catalyst layer is formed by a wet coating process using catalyst inks. Therefore, it is very important to observe the microstructure of the catalyst ink. In this study, the morphology of carbon-supported platinum (Pt/C) particles in catalyst inks with a different solvent composition was investigated by cryogenic scanning electron microscopy (cryo-SEM). In addition, the morphology of the ionomer, which presumably influences the formation of agglomerated Pt/C particles in a catalyst ink, was investigated by cryogenic transmission electron microscopy (cryo-TEM). The results of a cryo-SEM observation revealed that the agglomerated Pt/C particles tended to become coarser with a higher 1-propanol (NPA) weight fraction. The results of a cryo-TEM observation indicated that the actual ionomer dispersion in a catalyst ink formed a network structure different from that of the ionomer in the solvent.
Functional Analysis Department, Nissan ARC Ltd., 1 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
Junichi
J
Shimanuki
Research Division, Nissan Motor Co., Ltd., 1 Natsushima-cho, Yokosuka, Kanagawa 237-8523, Japan.
Shinichi
S
Takahashi
Functional Analysis Department, Nissan ARC Ltd., 1 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
Hajime
H
Tohma
Research Division, Nissan Motor Co., Ltd., 1 Natsushima-cho, Yokosuka, Kanagawa 237-8523, Japan.
Atsushi
A
Ohma
Industry Division, Leica Microsystems, 1-29-9 Takadanobaba, Shinjuku, Tokyo 169-0075, Japan.|Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.|RSC-University of Hyogo Leading Program Center, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
Ayumi
A
Ishihara
Industry Division, Leica Microsystems, 1-29-9 Takadanobaba, Shinjuku, Tokyo 169-0075, Japan.|Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.|RSC-University of Hyogo Leading Program Center, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
Yoshiko
Y
Ito
Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.|RSC-University of Hyogo Leading Program Center, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
Yuri
Y
Nishino
Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan.|RSC-University of Hyogo Leading Program Center, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
Atsuo
A
Miyazawa
cryo-SEM; cryo-TEM; cryo-ultramicrotome; fuel cell catalyst inks; high-pressure freezer; plunge freezer