Development of Molecular Catalysts Promoting Multi-electron Reduction Reactions via Unique Proton-coupled Electron Transfer Pathways

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05150
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 34010:Inorganic/coordination chemistry-related
• Research Institution: Kyushu University
• Principal Investigator: Yamauchi Kosei 九州大学, 理学研究院, 助教 (50631769)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 人工光合成 / プロトン共役電子移動（PCET） / 錯体触媒 / 水素生成

Outline of Final Research Achievements

We studied the unique proton-coupled electron transfer (PCET) processes which are promoted at either the metal or ligand center. Specifically, we succeeded in developing the new molecular catalyst which promotes hydrogen evolution from water with the exceptionally overpotential of 173 mV by enhancing PCET at the ligand center. Furthermore, DFT calculations were performed to elucidate the factors controlling the ligand-centered PCET leading to hydrogen evolution from water. In addition, advanced electrochemical reaction analysis was performed to experimentally elucidate the reaction mechanism. On the other hand, we developed the new photochemical system which promotes hydrogen evolution from water via metal-centered PCET.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

プロトンと電子が協奏的に移動するプロトン共役電子移動（PCET）は、生体系の重要反応を担い、これまで多くの研究がなされてきた。一方、PCETを効果的に活用し、高効率な人工光合成系を構築した研究例はほとんどない。本研究では、機能性配位子上で進行する特異なPCETを巧みに制御することにより水素生成錯体触媒の過電圧を劇的に低下させることに成功した。また、機能性錯体上で進行するPCET過程の反応制御因子を実験的並びに計算化学的に解き明かした。このように、特異なPCETを経由し水素生成反応を促進する分子性触媒について多角的な研究を展開し、同分野の発展に貢献する種々の価値ある成果を収めた。