Development of photocatalytic systems for the production of C2 compounds

• Project/Area Number: 19K05511
• 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: Tokyo University of Technology
• Principal Investigator: MORIMOTO Tatsuki 東京工科大学, 工学部, 准教授 (40452015)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2021: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2020: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: 光触媒 / 人工光合成 / 二酸化炭素還元 / 多核錯体 / 電子アクセプター / 強発光性 / 多量体 / 多電子貯蔵 / C2化合物 / レニウム錯体 / 環状化合物

Outline of Research at the Start

光触媒的二酸化炭素（CO2）還元反応の実用化に向けて、複数の炭素原子を含む炭素化合物を生成する新規光触媒の開発を設定した。２個のレニウム錯体を近接した位置に配置した二核金属錯体光触媒、および、それを効率的に動作させるための、可視光で多電子を駆動・蓄積する電子プールを設計し、これらを連結することで、シュウ酸などの複数の炭素原子を含む化合物を与える新しい多電子還元光触媒系の実現を目指す。

Outline of Final Research Achievements

New photocatalysts, based on dinuclear- or trinuclear-metal complexes, were designed for photocatalytic systems producing multi-carbon compounds from carbon dioxide (CO2). Several multinuclear complexes, where metal centers were forced to be close to each other by covalent bonds or conformations, were synthesized and the photocatalytic ability was examined. Although no candidates were found to reduce CO2 to multi-carbon compounds, it was revealed that some multinuclear complexes showed higher photocatalytic ability for CO2 reduction to carbon monoxide. Furthermore, it was also found that the distance between metal centers or the conformations affect the photocatalytic performance, which can be a new design criteria for effective photocatalysts for CO2 reduction.

Academic Significance and Societal Importance of the Research Achievements

地球規模の様々な問題に関わっている二酸化炭素(CO2)の処理方法の一つとして、人工光合成によるCO2の再資源化が有望視されている。本研究では、多核化した特定の金属錯体が、従来のCO2還元反応系を上回ることを見出した。さらに、そのCO2還元の効率化が、錯体中の金属中心間の距離や立体配座によることも明らかにし、CO2還元金属錯体光触媒の設計指針の一つを提案できた。

Research Products

• [Journal Article] Determining Excited-State Structures and Photophysical Properties in Phenylphosphine Rhenium(I) Diimine Biscarbonyl Complexes Using Time-Resolved Infrared and X-ray Absorption Spectroscopies (2021)
  • Author(s): Yuushi Shimoda, Kiyoshi Miyata, Masataka Funaki, Takumi Ehara, Tatsuki Morimoto, Shunsuke Nozawa, Shin-ichi Adachi, Osamu Ishitani, Ken Onda
  • Journal Title: Inorganic Chemistry Volume: 60 Issue: 11 Pages: 7773-7784
  • DOI: 10.1021/acs.inorgchem.1c00146
  • Peer Reviewed / Open Access
• [Journal Article] Ion-pairing π-electronic systems: ordered arrangement and noncovalent interactions of negatively charged porphyrins (2021)
  • Author(s): Sasano Yoshifumi、Tanaka Hiroki、Haketa Yohei、Kobayashi Yoichi、Ishibashi Yukihide、Morimoto Tatsuki、Sato Ryuma、Shigeta Yasuteru、Yasuda Nobuhiro、Asahi Tsuyoshi、Maeda Hiromitsu
  • Journal Title: Chemical Science Volume: 12 Issue: 28 Pages: 9645-9657
  • DOI: 10.1039/d1sc02260a
  • Peer Reviewed
• [Journal Article] Increase in CO2 reduction rate via optical near-field effect (2020)
  • Author(s): Takashi Yatsui, Yuki Nakamura, Yosuke Suzuki, Tatsuki Morimoto, Yuma Kato, Muneaki Yamamoto, Tomoko Yoshida, Wataru Kurashige, Nobuyuki Shimizu, Yuichi Negishi, Kenji Iida, Katsuyuki Nobusada
  • Journal Title: Journal of Nanophotonics Volume: 14 Issue: 04 Pages: 046011-046011
  • DOI: 10.1117/1.jnp.14.046011
  • Peer Reviewed / Open Access
• [Journal Article] Realization of red shift of absorption spectra using optical near-field effect (2019)
  • Author(s): Yatsui Takashi、Nakahira Yusuke、Nakamura Yuki、Morimoto Tatsuki、Kato Yuma、Yamamoto Muneaki、Yoshida Tomoko、Iida Kenji、Nobusada Katsuyuki
  • Journal Title: Nanotechnology Volume: 30 Issue: 34 Pages: 34LT02-34LT02
  • DOI: 10.1088/1361-6528/ab2092
  • Peer Reviewed
• [Presentation] Photocatalytic CO2 reduction by multinuclear rhenium complexes having metal centers separated by various distances (2022)
  • Author(s): 飯嶋理恵・森本樹
  • Organizer: 日本化学会 第102春季年会(2022)
• [Presentation] Photocatalytic CO2 Reduction by Multinuclear Rhenium Complexes with Various Conformers (2021)
  • Author(s): Rie Iijima, Tatsuki Morimoto
  • Organizer: 16th International Workshop on Supramolecular Nanoscience of Chemically Programmed Pigments
  • Int'l Joint Research
• [Presentation] レニウム多核錯体を用いた光触媒的CO2還元 (2021)
  • Author(s): 飯嶋理恵・森本樹
  • Organizer: 第13回大学コンソーシアム八王子学生発表会
• [Presentation] 立体配座を規制したレニウム三核錯体による光触媒的二酸化炭素還元 (2020)
  • Author(s): 飯嶋 理恵, 森本 樹
  • Organizer: 錯体化学会 第70回討論会
• [Presentation] Photocatalytic CO2 reduction by trinuclear rhenium complexes (2020)
  • Author(s): IIJIMA, Rie; MORIMOTO, Tatsuki
  • Organizer: 日本化学会第100春季年会
• [Book] 錯体化合物事典 (2019)
  • Author(s): 錯体化学会
  • Total Pages: 1000
  • Publisher: 朝倉書店
  • ISBN: 9784254141054
• [Remarks] 東京工科大学・工学部応用化学科・光機能性錯体化学研究室
  • URL: http://www.cloud.teu.ac.jp/public/ENF/morimotottk/index.html