# US 12,015,161 B2 · Catalyst for solid polymer fuel cell and method for selecting catalyst for solid polymer fuel cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,161 B2 - Document ID: US12015161B2 - Status: Granted - Kind: B2 - Application number: 17/269,891 - Filed: 2019-08-15 - Published: 2021-10-21 - Granted: 2024-06-18 - Earliest claimed: 2018-08-22 - Assignees: Tanaka Kikinzoku Kogyo K.K. - Applicants: Tanaka Kikinzoku Kogyo K.K. - Inventors: Minoru Ishida - Web page: https://patentgrep.com/patent/US12015161B2 ## CPC - C23C 18/1635: {Composition of the substrate} - H01M 4/926: {on carbon or graphite} - C23C 18/1692: {Heat-treatment} - G01N 23/2273: Measuring photoelectron spectrum, e.g. electron spectroscopy for chemical analysis [ESCA] or X-ray photoelectron spectroscopy [XPS] - H01M 4/8657: {layered} - H01M 4/8663: {Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers} - H01M 4/921: {Alloys or mixtures with metallic elements} - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C23C 18/34: using reducing agents - C23C 18/50: with alloys based on iron, cobalt or nickel - H01M 4/923: {Compounds thereof with non-metallic elements} - H01M 2008/1095: {Fuel cells with polymeric electrolytes} - Y02E 60/50: Fuel cells - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present invention relates to a catalyst for solid polymer fuel cells in which catalyst particles containing Pt as an essential catalyst metal are supported on a carbon powder carrier. The catalyst has good initial activity and good durability. When the catalyst is analyzed by X-ray photoelectron spectroscopy after potential holding at 1.2 V (vs. RHE) for 10 minutes in a perchloric acid solution, a ratio of zero-valent Pt to total Pt is 75% or more and 95% or less. The present inventive catalyst metal is preferably one obtained by alloying Pt with one of Co, Ni and Fe, and further with one of Mn, Ti, Zr and Sn. In addition, it is preferable that a fluorine compound having a C—F bond is supported on at least the surfaces of catalyst particles in an amount of 3 to 20 mass % based on the total mass of the catalyst. ## Claims ### Claim 1 A catalyst for solid polymer fuel cells comprising (A) catalyst particles comprising (a) a carbon powder carrier; and (b) Pt as a catalyst metal supported on the carbon powder carrier; and (B) a fluorine compound having a C—F bond is supported on at least surfaces of the catalyst particles, and a supporting amount of the fluorine compound is 3 to 20 mass % based on a total mass of the catalyst, wherein when the catalyst for solid polymer fuel cells is analyzed by X-ray photoelectron spectroscopy analysis after potential holding at 1.2 V (vs. RHE) for 10 minutes in a perchloric acid solution, a ratio of zero-valent Pt to total Pt as measured by the analysis is 75% or more and 95% or less. ### Claim 2 (depends on 1) The catalyst for solid polymer fuel cells according to claim 1, wherein the ratio of tetravalent Pt to total Pt is 1.5% or less as measured by the analysis. ### Claim 3 (depends on 1) The catalyst for solid polymer fuel cells according to claim 1, wherein the catalyst particles comprise Pt and metal M1 as catalyst metals, and the metal M1 is one of Co, Ni and Fe. ### Claim 4 (depends on 3) The catalyst for solid polymer fuel cells according to claim 3, wherein the catalyst particles comprise Pt, metal M1 and metal M2 as catalyst metals, and the metal M2 is one of Ni, Fe, Mn, Ti, Zr and Sn. ### Claim 5 (depends on 1) The catalyst for solid polymer fuel cells according to claim 1, wherein the fluorine compound is a fluororesin or a fluorine-based surfactant. ### Claim 6 (depends on 1) The catalyst for solid polymer fuel cells according to claim 1, wherein a supporting density of the catalyst particles is 30 to 70%. ### Claim 7 A method for selecting a catalyst which is manufactured by any method and which is used for an electrode of a solid polymer fuel cell, comprising the steps of: subjecting the catalyst to potential holding treatment for 10 minutes at a constant potential of 1.2 V (vs. RHE) in a perchloric acid solution; analyzing the catalyst after the potential holding treatment by X-ray photoelectron spectroscopy analysis to measure a Pt spectrum of surfaces of catalyst particles of the catalyst; and calculating a ratio of zero-valent Pt to total Pt by the analysis, and it is determined that the catalyst is suitable for use when the ratio is 75% or more, wherein an electrochemical control apparatus for the treatment of the catalyst at the constant potential and an analysis chamber of an XPS apparatus for performing the X-ray photoelectron spectroscopic analysis communicate with each other in a vacuum state, and the X-ray photoelectron spectroscopic analysis is performed after the catalyst that has been subjected to the treatment at the constant potential is adapted not to come into contact with oxygen. ### Claim 8 (depends on 2) The catalyst for solid polymer fuel cells according to claim 2, wherein the catalyst particles comprise Pt and metal M1 as catalyst metals, and the metal M1 is one of Co, Ni and Fe. ### Claim 9 (depends on 2) The catalyst for solid polymer fuel cells according to claim 2, wherein a supporting density of the catalyst particles is 30 to 70%. ### Claim 10 (depends on 3) The catalyst for solid polymer fuel cells according to claim 3, wherein a supporting density of the catalyst particles is 30 to 70%. ### Claim 11 (depends on 4) The catalyst for solid polymer fuel cells according to claim 4, wherein a supporting density of the catalyst particles is 30 to 70%. ### Claim 12 (depends on 1) The catalyst for solid polymer fuel cells according to claim 1, wherein a supporting density of the catalyst particles is 30 to 70%. ### Claim 13 (depends on 5) The catalyst for solid polymer fuel cells according to claim 5, wherein a supporting density of the catalyst particles is 30 to 70%.