Devlopment of Molecular Catalysts Promoting Consecutive Reductions of Carbon Dioxide with High Selectivity

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05100
• 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): 2021-04-01 – 2024-03-31
• Keywords: 二酸化酸素還元 / 人工光合成 / エネルギー変換 / N-ヘテロ環状カルベン（NHC） / 水素発生 / 電気化学 / 光化学 / メタン

Outline of Final Research Achievements

In this study, photochemical and electrochemical carbon dioxide (CO2) reduction catalyzed by various Co-NHC complexes was investigated in detail. In the photochemical system, the main product is CO, the two-electron reduction product of CO2, and a significant enhancement of catalytic properties in the presence of acid source was observed. In the electrochemical system, methane (CH4) was found to be produced in small amounts during the controlled potential electrolysis of the catalyst solution. This result suggests that the CO captured over the metal center was activated and led to the subsequent consecutive multi-electron reduction process.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

持続可能な社会の実現を目指し、地球温暖化の主要因である二酸化炭素（CO2）の有用化合物への変換反応に関する研究が盛んに行われている。COやギ酸などのCO2の２電子還元生成物を与える分子性触媒反応系の報告は多数あるが、エネルギーキャリアとして真に有用であるメタノール（６電子還元生成物）やメタン（８電子還元生成物）を与える反応系はほとんど無い。本研究では、CO2雰囲気で微量ながらもメタンを生成する分子性触媒系を構築することができ、今後の高選択的なCO2変換系への展開が期待できる。