The National Science Foundation's (NSF) Tokyo Office periodically receives and disseminates reports on research developments in Japan that are related to the Foundation's mission. NSF-sponsored researchers currently working in Japan prepare many of these reports. These reports present information for use by NSF program managers and policy makers; they are not statements of NSF policy.
Special Scientific Report #01-02 (August 28, 2001)
Electrochemical Phenomena and Catalysis Research in Japan
The following report was prepared by Geoffrey Prentice, Program Director for Kinetics, Catalysis and Molecular Processes in the National Science Foundation's Directorate for Engineering. Dr. Prentice was in Japan from June 17th to June 30th, 2001, on a Japan Society for the Promotion of Science (JSPS) Short Term Invitational Fellowship. Professor Zempachi Ogumi of the Department of Energy and Hydrocarbon Chemistry at Kyoto University served as his host. Dr. Prentice may be reached at gprentic@nsf.gov
Overview
In my current position as a program director for Kinetics, Catalysis, and Molecular Processes (KCMP) at the National Science Foundation (NSF), I administer funding for research primarily in catalysis, electrochemical and photochemical phenomena. I was able to visit a number of Japanese universities where research in fields of interest to my program is active. The list of faculty contacts is appended. During the first week I visited Kyoto University and made trips to Osaka University and to Osaka Prefecture University. During the second week, I moved to Tokyo to visit Tokyo Institute of Technology. I traveled from Tokyo to Sendai to visit Tohoku University before returning to Kyoto.
Support is available from KCMP for cooperative research with international collaborators and for educational activities. I gave a presentation on these activities at the universities I visited. Several KCMP grantees have visited Japan and expressed interest in collaborations with specific Japanese faculty. Although there are a number of international collaborative activities supported by KCMP, there are no current, formal collaborations with Japanese faculty. Through my presentations, I expected to increase awareness of the modes of support for collaborative activities.
During my visits, my hosts and their associates were all very hospitable and helpful. I especially appreciate the efforts of my host, Professor Zempachi Ogumi, who coordinated my visits and arranged my accommodations at each university. His associates, staff, and family made my visit to Japan most enjoyable and productive.
Kyoto University
At Kyoto University I met with Prof. Ogumi and his research staff, Drs. Minoru Inaba, Takeshi Abe, and Yasutoshi Iriyama. Most of their research effort is aimed at electrochemical energy conversion and storage. There is a wide spectrum of work focused on fuel cells, secondary lithium batteries, and solid polymer electrolytes. Their work is largely fundamental with over 90% of the funding coming from government sources such as JSPS, JST, and NEDO. Electrode reactions are being studied in a range of fuel-cell systems including solid-oxide fuel cells (SOFC), polymer electrolyte membrane (PEM) fuel cells, and direct methanol fuel cells (DMFC). The PEM and DMFC systems are attracting more attention as fuel-cell systems likely to gain widespread commercial application. Corporations such as Toyota and Motorola have announced plans to use fuel cells in automotive and electronics applications.
Prof. Ogumi's group is active in studying the kinetics of electrode reactions critical for the improvement devices. They are studying oxygen reduction on gold electrodes and investigating the effects of the membrane film on the kinetics of hydrogen oxidation. Studies on a novel alkaline carbonate system for use with methanol near room temperature is aimed at overcoming the problem with methanol diffusion (crossover) through the membrane. In more advanced SOFCs, his group is preparing novel thin films of yttria-stabilized zirconia using electrochemical vapor deposition.
Another main theme in Prof. Ogumi's group is a study of the fundamental processes at the anode in electrodes useful in lithium-ion batteries. They are growing carbonaceous films by novel methods and performing experiments to characterize the charge/discharge characteristics with lithium ions. Carbonaceous thin films prepared with plasma chemical vapor deposition (CVD) show promise for this application.
Prof. Masashi Inoue at Kyoto University is performing novel syntheses of nanoparticles from organic phases. Although inorganic materials are routinely synthesized by hydrothermal methods, the production of inorganic particles from glycols and other organic media is a relatively new field. This work is yielding monodisperse particles of compounds containing iron, aluminum, cerium, titanium, and rare earth elements. In particular, the rare earth-iron perovskite phases are of interest for catalysts and sensors. Titanium dioxide nanoparticles have been produced by glycothermal methods; these particles possess high thermal stability and have the potential for use in photocatalytic decomposition of toxic organic materials. Two-nanometer ceria particles, containing about 100 cerium atoms, have been produced from organic media. These compounds are capable of storing and releasing oxygen and are of technological importance in the reduction automotive pollutants as a component of the catalytic converter.
Prof. Takashi Kakiuchi's group is concerned with interfacial processes at the electrode/electrolyte interface. Theoretical work is based on first-principles calculations for the electronic density in the metal and for the orientation and density of molecules in the liquid phase. Experimental work on well-characterized gold electrodes complements the theoretical work. Immobilized enzymes on electrode surfaces are being studied for potential applications in multistep syntheses and for sensors.
Osaka University
At Osaka University my host was Prof. Susumu Kuwabata. His group is synthesizing new materials for secondary lithium-ion battery cathodes. They are fabricating novel composites from metal oxides and conductive polymers and testing the charge/discharge characteristics for potential application as cathodes. Manganese dioxide and vanadium oxide coupled with polypyrrole, polyaniline and other polymers are being tested. This composite concept may lead to improved cathodes. Another research area is amperometric detection of organic molecules on enzyme electrodes; such electrodes may be useful for the rapid detection of cholesterol.
Osaka Prefectural University
At Osaka Prefectural University my host was Prof. Chiaki Iwakura. The general theme of his research is the storage of hydrogen and electrochemical hydrogenation reactions. His group is synthesizing new electrode alloys for use in the technologically important nickel-metal hydride batteries. The novel titanium-vanadium-nickel alloys they are synthesizing have high capacity for hydrogen storage and are candidate materials for the negative battery electrode. Other alloys are being considered for use in the electrochemical hydrogenation of unsaturated organic compounds.
The study of the fundamental processes of photocatalysts for the production of fuel, for the decomposition of pollutants, and for chemical synthesis is the primary goal of Prof. Masakazu Anpo's group. Their novel metal-ion-implantation method for introducing transition metal ions into titanium dioxide is increasing the response of this photocatalytic material to the visible portion of the solar spectrum. The decomposition of nitric oxide on zeolites containing titanium oxides and on titanium dioxide thin films is being investigated. This work has the potential to decompose oxides of nitrogen to nitrogen gas.
Tokyo Institute of Technology
At the Suzukakedai campus of the Tokyo Institute of Technology, Prof. Yohtaro Yamazaki was my host. His work has centered on synthesizing and characterizing magnetic thin films for memory storage applications. He is currently applying his materials expertise to the fabrication of fuel-cell membranes. Prof. Kazunari Domen is investigating two novel approaches to the photocatalytic decomposition of water. In one approach he has discovered that mechanical energy can assist the decomposition process; this represents pioneering work on mechano-catalytic phenomena. In a second approach he is incorporating niobium, zirconium, and lanthanum into perovskite structures, which have been shown to be highly effective in hydrogen production through photocatalytic processes.
Tohoku University
At Tohoku University (Sendai) my host was Prof. Akira Miyamoto. Although I met with a number of faculty at Tohoku, the work most relevant to my program was performed by Profs. Miyamoto, Itaya, and Yamada. Prof. Miyamoto is well known for his work in molecular modeling. His efforts are to expand the field into new areas such as nanotribology, crystal growth, and adsorption. His work on the use of molecular modeling to guide combinatorial catalysis should accelerate the discovery of new catalytic materials. Prof. Itaya's work on the processes occurring at the atomic level through scanning tunneling microscopy is elucidating the structure of surfaces in technologically important systems such as silicon single crystals and gallium arsenide. Prof. Yamada's work on sulfur reduction in fuels and on the reduction nitrogen oxides from combustion processes has implications for maintaining a cleaner environment. Sulfur reduction in fuels through hydrodesulfurization using cobalt and molybdenum catalysts is particularly relevant for the stricter standards being imposed by regulatory authorities in both Japan and the US.
Observations
During my brief trip to a small sample of Japanese universities, my impression of the research enterprise at the universities was overwhelmingly positive. Faculty are focused on critical problems and are considering innovative approaches. There is an effective blend of complementary theoretical and experimental work. Many faculty have projects that range from highly speculative to relatively applied. Facilities and equipment are generally more than adequate, and cooperation among faculty at different Japanese universities is a regular feature with mutual benefits. Many faculty publish in internationally recognized journals and maintain regular contacts with faculty at foreign universities.
Faculty explained that cooperation with industry is now being more highly promoted and that universities could now pursue patents for their work. Industrial consulting by faculty is now permitted. I regard these changes as positive developments. I was surprised to learn that the majority of graduate students in science and engineering provide most of their own support. This feature speaks to the dedication of Japanese graduate students I met; however, a shortage of graduate students was noted, and graduate students from abroad were recruited. Although I met with a small number of female graduate students, I did not meet with any female faculty. It appears that the number of women faculty in science and engineering is relative small.
Japanese corporations have been in the forefront of technological developments related to several areas relevant to my program. About a decade ago Sony Corporation successfully commercialized the secondary lithium-ion battery, and there is currently significant research at several universities supporting fundamental work that could lead to improvements in this system. Japanese auto companies have developed technologically advanced vehicles. The Toyota Prius hybrid vehicle, which employs nickel-metal hydride technology, has been popular in both the US and Japan; there is significant work related to the nickel-metal hydride battery in university laboratories. A number of corporations, including Toyota, have announced their intention to develop vehicles powered by fuel cells, which are being investigated at academic institutions. Japanese investigators are particularly active in photocatalytic processes, and I was impressed by the breadth of novel approaches in this area. This technology has advanced to the development stage in a number of areas, most notably in the application of titanium dioxide to the walls surrounding highways to photodecompose polluting nitrogen oxides.
Acknowledgements
I wish to thank my hosts, all of whom were most kind and generous with their time. I also appreciate the generous support that JSPS provided for this study tour. I hope that I was successful in making more of the Japanese faculty aware of the potential for cooperative activities with their US counterparts.
Faculty and Staff Contacts
Kyoto University: Zempachi Ogumi, Minoru Inaba, Takeshi Abe, Yasutoshi Iriyama, Masashi Inoue, Takashi Kakiuchi, Masataka Tanigaki
Osaka University: Susumu Kuwabata, Nobuhito Imanaka, Toshiyuki Masui
Osaka Prefectural University: Chiaki Iwakura, Hiroshi Inoue, Naoji Furukawa, Shinji Nohara, Masakazu Anpo
Tokyo Institute of Technology: Yohtaro Yamazaki, Michikazu Hara, Kazunari Domen
Tohoku University: Akira Miyamoto, Kunio Arai, Kingo Itaya, Norio Teramae, Muneyoshi Yamada, Tomokazu Matsue, Junji Inukai, Richard Smith, Takashi Hayashita, Momoji Kubo, Seiichi Takami
NSF Tokyo Regional Office: William Blanpied