Abstract: A metal-supported catalyst, a battery electrode, and a battery, each having both excellent catalytic activity and durability. The metal-supported catalyst includes: a carbon carrier; and platinum particles serving as catalyst metal particles supported on the carbon carrier, wherein the platinum particles contain pure platinum particles and platinum alloy particles, wherein a proportion of a weight of the pure platinum particles to a sum of the weight of the pure platinum particles and a weight of the platinum alloy particles is 15% or more and 61% or less, and wherein a ratio of a proportion of a nitrogen atom content to a carbon atom content measured by elemental analysis using a combustion method, to a proportion of a nitrogen atom content to a carbon atom content measured by X-ray photoelectron spectroscopy, is 1.05 or more.

Abstract: A metal-supported catalyst, battery electrode, and battery, each having excellent catalytic activity and durability. The metal-supported catalyst includes: a carbon carrier; and catalyst metal particles supported thereon, wherein, in a photoelectron spectrum obtained by X-ray photoelectron spectroscopy, the catalyst exhibits, as a peak derived from a is orbital of a nitrogen atom, a peak to be separated into peaks of first to sixth nitrogen atoms having peak tops in the following respective ranges: (1) 398.6±0.2 eV; (2) 399.5±0.3 eV; (3) 400.5±0.2 eV; (4) 401.3±0.3 eV; (5) 403.4±0.4 eV; and (6) 404.5±0.5 eV, wherein a ratio of a peak area of the second nitrogen atoms to a total peak area of the nitrogen atoms of the (1) to (6) is 0.03 or more, and wherein a ratio of a concentration of the second nitrogen atoms to a concentration of carbon atoms measured by the X-ray photoelectron spectroscopy is 0.0005 or more.

Abstract: A metal-supported catalyst, a battery electrode, and a battery, each having both excellent catalytic activity and durability. The metal-supported catalyst includes: a carbon carrier; and catalyst metal particles each containing a noble metal supported on the carbon carrier, wherein a volume of first pores each having a diameter of 0.5 nm or more and 2.0 nm or less per unit weight of the carbon carrier is 0.20 (cm3/g-carrier) or more, wherein a volume of second pores each having a diameter of more than 2.0 nm and 4.0 nm or less per unit weight of the carbon carrier is 0.20 (cm3/g-carrier) or more, and wherein a ratio of a content (wt %) of the noble metal measured by X-ray photoelectron spectroscopy, to a content (wt %) of the noble metal measured by inductively coupled plasma mass spectrometry, is 0.35 or more and 0.75 or less.