Proximity Effect of Enzymes and Metal Complex Catalysts on Selective Oxidation

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14648
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 34010:Inorganic/coordination chemistry-related
• Research Institution: Kyoto University (2023); Osaka City University (2021)
• Principal Investigator: Tabe Hiroyasu 京都大学, 高等研究院, 特定講師 (50803764)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 固定化触媒 / 酸化還元 / 光触媒 / 配位高分子

Outline of Final Research Achievements

The aim of this Kakenhi project is preparation of composite catalysts consisting of multiple catalytic moieties such as metal complexes and enzymes. Glassy coordination polymers are good candidates to be used to simultaneously immobilize multiple catalytic components more rationally to integrate their catalytic functions. A proton (H+) conducting coordination polymer glass was chosen as a support of iron (Fe) complex acting as CO2 reduction under the visible-light irradiation. The CO2 reduction requires the supply of H+, indicating that the catalysis enhancement is expected by the immobilization in H+-conductive materials. The results of photocatalytic reactions showed that the yield of carbon monoxide (CO) was proportional to the thickness of the glass membranes. The results indicates that light reached the Fe-complex catalysts fixed on subsurface of the transparent glass and CO2 and H+ were reacted in the subsurface.

Free Research Field

錯体化学

Academic Significance and Societal Importance of the Research Achievements

触媒担体は繰返し使用に置ける堅牢性、不溶性に着目して選定されることが多かったが、活性点を近接化する、あるいは担体のもつイオン伝導性や内部での基質拡散性を積極的に利用する例は少なかった。ガラス相のイオン伝導体に触媒を固定することで、当初課題名に掲げた通り、触媒活性点と機能性成分の近接化を実現できた。研究表題にある選択的酸化反応も、金属錯体を固定化した配位高分子ガラス膜を触媒として進行することを見出している（学会発表済）。
CO2還元反応、選択的酸化反応とも炭素循環社会の実現に資するものであり、本科研費課題で取り組んだ研究は社会的意義が大きいものであると確信している。