In the effort to realize a carbon-neutral society, Kyushu University has been investigating ways to more efficiently use and store hydrogen for several decades.
“We have been working on developing new materials that can store and transport hydrogen energy,” explains Professor Seiji Ogo of Kyushu University’s International Institute for Carbon-Neutral Energy Research, who led the research team. “Transporting it in its gaseous state requires significant energy. An alternative way of storing and transporting it would be to ‘split up’ the hydrogen atoms into its base components, electrons and protons.”
Many candidates have been considered as possible hydrogen energy carries such as ammonia, formic acid, and metal hydrides. However, the final energy carrier had not yet been established.
“So, we looked to nature for hints. There are a series of enzymes called hydrogenases that catalyze hydrogen into protons and electrons and can store that energy for later use, even at room temperature,” continues Professor Ogo. “By studying these enzymes, our team was able to develop a new compound that does exactly that.”
Not only was their new compound able to extract and store electrons at room temperature, but further investigations showed that it can be its own catalyst to extract electrons, something that had not been possible with previous hydrogen energy carriers. The team also showed that the energy could be stored for up the three months.
Professor Ogo also highlights the fact that the compound uses an inexpensive element: nickel. Until now, similar catalysts have used expensive metals like platinum, rhodium, or iridium. With nickel now being a viable option for hydrogen energy storage, it can potentially reduce the cost of future compounds.
The team intends to collaborate with the industrial sector to transfer their new findings into more practical applications.
“We would also like to work on improving storage time and efficiency as well as investigate the viability of cheaper metals for such compounds, ” concludes Professor Ogo. “Hopefully, our findings will contribute to the goal of decarbonization so that we can build a greener and environmentally friendly future.”