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.