Noble metal catalyst layer, membrane electrode assembly, and method for producing noble metal catalyst layer
AssigneeKabushiki Kaisha Toshiba
InventorsWu Mei, Shigeru Matake, Taishi Fukazawa, Yoshihiro Akasaka, Katsuyuki Naito
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Abstract
According to one embodiment, the noble metal catalyst layer includes first noble metal layer and a second noble metal layer formed on the first noble metal layer. The first noble metal layer includes a first noble metal element and has a porosity of 65 to 95 vol. %, a volume of pores having a diameter of 5 to 80 nm accounts for 50% or more of a volume of total pores in the first noble metal layer. The second noble metal layer includes a second noble metal element, and has an average thickness of 3 to 20 nm and a porosity of 50 vol. % or less.
Claims18
A noble metal catalyst layer comprising:
- a first noble metal layer which comprises a first noble metal element and a cavity having a diameter of 100 nm or more, the first noble metal layer excluding the cavity having a porosity of 65 to 95 vol. %, a volume of pores having a diameter of 5 to 80 nm accounting for 50% or more of a volume of the total pores excluding the cavity in the first noble metal layer;
- and
- second noble metal layers which are formed on both sides of the first noble metal layer, comprise a second noble metal element and have an average thickness of 3 to 20 nm and a porosity of 50 vol. % or less,
- wherein the noble metal catalyst layer has an overall porosity of 20 vol. % or more, and an amount of a porous part of the first noble metal layer and the second noble metal layers in the noble metal catalyst layer is 60 vol. % or more.
Dependencies are inferred from the claim text.