Addressing safety risks and energy loss for a society with hydrogen energy
A research group led by Professor Hiroyuki Nishide and Professor Kenichi Oyaizu from the Department of Applied Chemistry developed a hydrogen-carrying polymer, which can be molded as a tangible, safe, and compact plastic sheet.
Although technology developments and research on realizing hydrogen as a major energy source have gone under way, the conventional methods of storing and carrying hydrogen were accompanied by safety risks such as explosions. Hence, hydrogen-exposed organic compounds have been recently studied as hydrogen storage materials, for their ability to stably and reversibly store hydrogen by forming chemical bonds. However, these compounds require vessels or sealed tanks operated at high pressure and/or temperature and often encounter difficulty in their separation from the evolved hydrogen gas. A much safer and more efficient system for storing and storing and carrying hydrogen has been in demand.
The research group discovered that ketone (fluorenone) polymer, which can be molded as a plastic sheet, can fix hydrogen via a simple electrolytic hydrogenation at -1.5V (versus Ag/AgCl) in water at room temperature. On the other hand, fluorenol polymer, a hydrogenated alcohol derivative of fluorenone, can release hydrogen when heated at 80 degree Celsius with an aqueous iridium catalyst. What’s more, the group proved that the cycle of repeatedly fixing and releasing hydrogen under mild conditions without significant deterioration, leading to the developement of a portable, plastic ketone polymer with hydrogen that can be carried around in your pocket.
The advantages of the ketone/alcohol polymer include easy handling, moldability, robustness, non-flammability and low toxicity, and the research results are expected to make contributions in building distributed energy systems in regional areas.
Simpler process and higher efficiency creates great expectations for consumer market
Waseda University researchers have developed a new method for producing hydrogen, which is fast, irreversible, and takes place at much lower temperature using less energy. This innovation is expected to contribute to the spread of fuel cell systems for automobiles and homes.
Hydrogen has normally been extracted from methane and steam using a nickel catalyst at temperatures of over 700°C. However, the high temperature creates major challenges for widespread use.
The group led by Professor Yasushi Sekine, Waseda University Faculty of Science and Engineering, developed a method which allows hydrogen extraction at temperatures as low as 150~200°C. This shift greatly reduces energy input needed to produce hydrogen fuel, extends catalyst life, reduces the cost of construction materials, and reduces complexity of heat-management (cooling) systems.
Although the research group had already seen that a fast reaction would be possible even in the range of 150~200°C by applying a weak electric fields (surface protonics), the mechanism had not been fully understood.
In this research, the group is the first to explain the mechanism by observing the catalyst during reaction. Protons move quickly through water adsorbed on the catalyst’s surface, and protons’ surface “hopping” allows reaction to proceed at low temperatures. Furthermore, the collision of the protons and the adsorbents prevents reversal of the reaction.
As momentum grows for the commercialization of hydrogen, this research is not only applicable to hydrogen production, but also to many consumer products since the same mechanism makes it possible to lower the temperature for various reactions involving hydrogen or water. The process is already being applied to research for improving energy efficiency in automobiles by creating reactions between exhaust gases and fuel at low temperature.
Waseda University (早稲田大学 Waseda Daigaku?), abbreviated as Sōdai (早大?), is a private university mainly located in Shinjuku, Tokyo, Japan.
As the second private university to be founded in Japan, Waseda University is considered to be one of Japan’s most prestigious universities, consistently ranking amongst the top universities in Japanese university rankings. The University has many notable alumni in Japan, with seven Prime Ministers of Japan and many CEOs, including Tadashi Yanai, the CEO of UNIQLO and wealthiest man in Japan.
Established in 1882 as the Tōkyō Senmon Gakkō by Ōkuma Shigenobu, the school was renamed Waseda University in 1902 after the founder’s hometown village. The university consists of 13 undergraduate schools and 23 graduate schools, and is one of the 13 universities in the Japanese Ministry of Education, Culture, Sports, Science and Technology’s “Global 30” Project.