| 摘要 |
PROBLEM TO BE SOLVED: To provide a base metal - noble metal composite nanoparticles usable as a precursor of catalyst particles that exhibit high catalytic performance, and a method for easily producing the composite nanoparticles, in particular, for producing an electrode catalyst preferable for application to a solid polymer electrolyte fuel cell.SOLUTION: There is provided the base metal - noble metal composite nanoparticles 1 in which nanoparticles 2 made of one or a plurality of noble metals are included in a matrix 3 of a base metal, and the base metal is metal having larger ionization tendency than hydrogen. There is provided the method for producing the composite nanoparticles 1, which includes: mixing a first water phase including base metal nanoparticles and a second water phase including ions of noble metal to dissolve base metal nanoparticles, thereby forming noble metal nanoparticles; and depositing the base metal on a surface of the noble metal nanoparticles to form the base metal - noble metal composite nanoparticles. In the base metal - metal composite nanoparticles, an average particle diameter of nanoparticles made of the noble metal is 1 to 10 nm, and an average particle diameter of the base metal - noble metal composite nanoparticles is 5 to 50 μm. |
