Prof. Iwasawa, Assoc. Prof. Takaya and Assoc. Prof. Maeda receive Prizes for Science and Technology in 2016 MEXT Commendation

Development of methods for the fixation of CO₂ as a carbon resource into useful organic compounds is one way to address the issue of dwindling fossil resources. Carbon dioxide's low reactivity, however, has been an obstacle to research and development of an efficient catalytic system for CO₂ fixation reactions.

Applying our unique transition metal catalysts or new catalyst systems, we reacted easily available organic molecules with CO₂, developed an efficient method capable of converting it to useful compounds, and successfully established a CO₂ fixation system.

This research achieved several new catalytic CO₂ fixation reactions that had conventionally been difficult to perform. These included the direct reaction of CO₂ with aromatic hydrocarbons and unsaturated hydrocarbons such as benzene and toluene. We are continuing our search for more efficient CO₂ fixation reactions.

These results were made possible by the perseverance of students working by trial and error to discover new possibilities as we struggled against defeat. I deeply appreciate the effort and energy they put into this project.

The creation and utilization of new molecules is one of the most important and interesting aspects of research in chemistry. We have synthesized new transition metal complexes bearing a group 14 element-centered pincer type ligand and successfully developed useful synthetic reactions of unreactive molecules such as carbon dioxide and unsaturated hydrocarbons utilizing these complexes as catalysts. We also clarified unprecedented non-innocent behavior of the group 14 elements as supporting ligands, which enabled new reaction mechanisms for bond activation and formation. These findings provide useful insights for designing transition metal catalysts in organometallic and synthetic organic chemistry.

It is a great honor to receive this award, and I want to express my appreciation to professor Nobuharu Iwasawa, my coworkers, and other faculty members for their generous support throughout this research.

I have been focusing on the development of a powder photocatalyst that generates hydrogen from water under sunlight. The importance of hydrogen as a clean energy carrier is increasing, and generating hydrogen from water and solar energy, both in abundant supply, would be a true breakthrough. A powder photocatalyst would potentially open up use in much larger areas exposed to plenty of sunlight, paving the way for future commercialization.

Through my research into artificial compounds that have not yet been reported, that is, materials that do not exist naturally, I have clarified that oxynitrides function as photocatalysts that are effective in splitting water under irradiation of sunlight. Furthermore, my work on promoting surface reactions with photocatalysts has for the first time resulted in a solar energy conversion efficiency comparable to that of natural photosynthesis in green plants.

Development of semiconductor photocatalyst and co-catalyst for visible light decomposition of water