Patents by Inventor Kazutaka Hiroshima

Kazutaka Hiroshima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7060385
    Abstract: The technique of the present invention attains simple and accurate evaluation of the performance of a fuel cell and enables produce of a high-performance electrode catalyst and a high-performance fuel cell. The procedure makes platinum, a noble metal, and iron, a base metal, carried on carbon having a large specific surface area, and heats up the carbon with platinum and iron to a specific temperature to reduce iron. A resulting platinum-iron alloy electrode catalyst exerts excellent catalytic functions. A fuel cell using this electrode catalyst has a high IR compensation voltage. The quantity of carbon monoxide adsorbed by this novel electrode catalyst is not less than 14 Ncc per one gram of platinum. The atomic number ratio of iron (Fe) to platinum (Pt) in the catalyst is not lower than 0.14 by EDX analysis, and the ratio of the binding number of Pt atom with Fe atom to the total binding number relating to Pt atom is not lower than 0.10 by EXAFS analysis.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: June 13, 2006
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hisao Kato, Takahiko Asaoka, Kazutaka Hiroshima
  • Patent number: 6911278
    Abstract: An electrode catalyst for a fuel cell includes a conductive support, and catalytic particles loaded on the conductive support. The catalytic particles include platinum and a base metal being on the lower end of the electrochemical series with respect to platinum. The number of the atoms of the base metal, forming metallic oxides without alloying with the platinum, is less than 5 atomic % of the number of the atoms of the platinum on a surface of the catalytic particles. The electrode catalyst is produced by loading the platinum and base metal on the conductive support, alloying the platinum and base metal thereon by a heat treatment, thereby making the catalytic particles, and removing metallic oxides from a surface of the catalytic particles. The electrode catalyst is less expensive comparatively, exhibits high catalytic activities, and hardly lowers the battery performance of fuel cells.
    Type: Grant
    Filed: August 27, 2002
    Date of Patent: June 28, 2005
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazutaka Hiroshima, Takahiko Asaoka, Yutaka Ohya, Tatsuo Noritake, Hisao Kato, Tetsuo Nagami
  • Publication number: 20030096156
    Abstract: In a powder-form electrode catalyzer for a fuel cell which comprises catalyst particles that contain platinum, and an electrically conductive support supporting the catalyst particles, the ratio between a mean value D111 of crystallite diameters of catalyst particles in a direction perpendicular to a (111) crystal face and a mean value D100 of crystallite diameters of the catalyst particles in a direction perpendicular to a (100) crystal face is D100/D111<1, and a mean crystallite diameter of the catalyst particles is at most 5 nm. Due to a large surface area that functions as a catalyst and a great proportion of the catalyst particles that have (100) crystal faces present on surfaces, the electrode catalyzer has high oxygen reduction activity.
    Type: Application
    Filed: November 8, 2002
    Publication date: May 22, 2003
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takahiko Asaoka, Kazutaka Hiroshima, Tatsuo Noritake, Yutaka Ohya, Hisao Kato, Tetsuo Nagami
  • Publication number: 20030054227
    Abstract: An electrode catalyst for a fuel cell includes a conductive support, and catalytic particles loaded on the conductive support. The catalytic particles include platinum and a base metal being on the lower end of the electrochemical series with respect to platinum. The number of the atoms of the base metal, forming metallic oxides without alloying with the platinum, is less than 5 atomic % of the number of the atoms of the platinum on a surface of the catalytic particles. The electrode catalyst is produced by loading the platinum and base metal on the conductive support, alloying the platinum and base metal thereon by a heat treatment, thereby making the catalytic particles, and removing metallic oxides from a surface of the catalytic particles. The electrode catalyst is less expensive comparatively, exhibits high catalytic activities, and hardly lowers the battery performance of fuel cells.
    Type: Application
    Filed: August 27, 2002
    Publication date: March 20, 2003
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazutaka Hiroshima, Takahiko Asaoka, Yutaka Ohya, Tatsuo Noritake, Hisao Kato, Tetsuo Nagami
  • Publication number: 20030044655
    Abstract: The technique of the present invention attains simple and accurate evaluation of the performance of a fuel cell and enables produce of a high-performance electrode catalyst and a high-performance fuel cell. The procedure makes platinum, a noble metal, and iron, a base metal, carried on carbon having a large specific surface area, and heats up the carbon with platinum and iron to a specific temperature to reduce iron. A resulting platinum-iron alloy electrode catalyst exerts excellent catalytic functions. A fuel cell using this electrode catalyst has a high IR compensation voltage. The quantity of carbon monoxide adsorbed by this novel electrode catalyst is not less than 14 Ncc per one gram of platinum. The atomic number ratio of iron (Fe) to platinum (Pt) in the catalyst is not lower than 0.14 by EDX analysis, and the ratio of the binding number of Pt atom with Fe atom to the total binding number relating to Pt atom is not lower than 0.10 by EXAFS analysis.
    Type: Application
    Filed: July 29, 2002
    Publication date: March 6, 2003
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hisao Kato, Takahiko Asaoka, Kazutaka Hiroshima
  • Patent number: 6500573
    Abstract: A humidifier device for use in fuel cells comprising a mist humidifier unit for adding mists to process gas supplied to an electrolyte equipped in a fuel cell and a humidifier unit control device for intermittently operating the mist humidifier unit in accordance with operating condition of the fuel cell.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: December 31, 2002
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Takashi Simazu, Hiroshi Aoki, Tomohisa Wakasugi, Takahiko Asaoka, Kazutaka Hiroshima, Yutaka Ohya, Katsuhito Yamada