Tanaka Kikinzoku Kogyo K.k.

Osaka University

Takeshi Kaieda

Koichi Matsutani

Hitoshi Nakajima

Wataru Hashimoto

Minoru Ishida

Yasushi Masahiro

Tomoyuki Tada

Hiroshi Nakanishi

Hideaki Kasai

Katsuichiro Hayakawa

Koji Shimizu

Tatsunori Namai

Kazuki Okaya

Tomohiro Akiyama

Provided are (i) a catalyst that has a core-shell structure and is highly active in an oxygen reduction reaction, which is a cathode reaction of a fuel cell, and (ii) a reaction acceleration method in which the catalyst is used. A core-shell catalyst for accelerating an oxygen reduction reaction, contains: silver or palladium as a core material; and platinum as a shell material, the core-shell catalyst having, on a surface thereof, a (110) surface of a face centered cubic lattice.

Cathode electrode catalyst of fuel cell, and reaction acceleration method

The present invention relates to a catalyst for solid polymer fuel cells in which catalyst particles including platinum or platinum alloy are supported on a carbon powder carrier. The catalyst of the present invention is a catalyst for solid polymer fuel cells in which the bond energy (Ec) at a gravity center position is 2.90 eV or more and 3.85 eV or less as calculated from a spectrum area of a Pt5d orbit-derived spectrum which is obtained by measuring a valence band spectrum in a range of 0 eV or more and 20 eV or less in the result of subjecting the catalyst particles to X-ray photoelectron spectroscopic analysis.

Catalyst for solid polymer fuel cells and method for manufacturing the same

The present invention relates to a catalyst for solid polymer fuel cells in which catalyst particles including platinum and a transition metal M are supported on a carbon powder carrier. The catalyst of the present invention is a catalyst for solid polymer fuel cells in which a molar ratio (Pt/M) of platinum to the transition metal M that form catalyst particles is 2.5 or more, and a ratio (S/S) of a platinum specific surface area (S) measured by a CO adsorption method to a catalyst specific surface area (S) measured by a BET method is 0.26 or more and 0.32 or less. The catalyst can be produced by preparing an alloy catalyst, then washing the alloy catalyst with a platinum compound solution, and additionally supplying platinum to the surfaces of catalyst particles.

Catalyst for solid polymer fuel cells and method for producing same

The present invention relates to a catalyst for a solid polymer fuel cell, including platinum, cobalt, and zirconium supported as a catalytic metal on a carbon powder carrier, in which the supporting ratio of platinum, cobalt, and zirconium on the carbon powder carrier is Pt:Co:Zr=3:0.5 to 1.5:0.1 to 3.0 by molar ratio. In the present invention, it is preferable that the peak position of PtCo seen in the X-ray diffraction pattern of catalyst particles is 2&#x3b8;=41.10&#xb0; or more and 42.00&#xb0; or less, and moderate alloying has occurred in the catalytic metal.

Catalyst for solid polymer fuel cell and method for producing same

A method for forming catalyst particles, each of which has a core/shell structure, by a Cu-UPD method. Namely, a method of manufacturing a catalyst wherein catalyst particles, each of which has a core/shell structure composed of a shell layer that is formed of platinum and a core particle that is covered with the shell layer and is formed of a metal other than platinum, are supported on a carrier. This method is characterized by comprising: an electrolysis step wherein the carrier supporting the core particles is electrolyzed in an electrolytic solution containing copper ions, so that copper is precipitated on the surfaces of the core particles; and a substitution reaction step wherein a platinum compound solution is brought into contact with the core particles, on which copper has been precipitated, so that the copper on the surface of each core particle is substituted by platinum, thereby forming a shell layer that is formed of platinum. This method is further characterized in that the platinum compound solution in the substitution reaction step contains citric acid.

Method for manufacturing catalyst having supported catalyst particles of core/shell structure

The present invention provides a catalyst for a polymer electrolyte fuel cell including catalyst particles made of platinum supported on a carbon powder carrier, wherein the carbon powder carrier includes 0.7 to 3.0 mmol/g (based on the weight of the carrier) of a hydrophilic group bonded thereto; and the platinum particles have an average particle size of 3.5 to 8.0 nm and the platinum specific surface area based on CO adsorption (COMSA) of 40 to 100 m/g. The catalyst for a polymer electrolyte fuel cell according to the present invention is a catalyst excellent in initial activity and satisfactory in durability.

Growing community of inventors

Hiratsuka, Japan

Takeshi Kaieda