Development of dehydrogenative cross-coupling reactions by blended catalysts

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21108
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: Kyoto University
• Principal Investigator: Yoshida Hisao 京都大学, 人間・環境学研究科, 教授 (80273267)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 光触媒 / カップリング

Outline of Final Research Achievements

Development of dehydrogenative cross-coupling (DCC) reactions were examined by using “blended catalyst” consisting of photocatalyst and supported metal catalyst. Methanol reforming reaction was conducted in a flow reactor, where photocatalyst and metal catalyst were set on the upstream and downstream, respectively, and the progress of the reaction to form molecular hydrogen confirmed the the assumed reaction mechanism with the blended catalyst is acceptable. Study of DCC reaction with many kinds of TiO2 photocatalyst statistically revealed that the photocatalytic reaction rate can be explained by the product of specific surface area and lifetime of the photoexcited electron hole pairs. Some new DCC reactions with pyridine were found, where the adsorbed molecules participate in the photoexcitation. Photocatalysts for dehydrogenative homo-coupling of methane or ethane were also developed. Finally, the blend catalyst has been developed by using metallic alloy catalysts.

Free Research Field

光触媒化学

Academic Significance and Societal Importance of the Research Achievements

光触媒と金属助触媒の物理混合（ブレンド触媒）、そのどちらか一方では達成できない化学反応も達成できることが示され、独立な触媒設計を可能とした点で今後の展開に対し意義深い。光触媒の反応速度が「比表面積と励起電子正孔の寿命の積」という指標で説明できることも示し長く議論されてきた構造物性活性相関に一つの解を与えたことも学問的に有意義である。新展開として、吸着分子光励起型のピリジンとのDCC反応や、メタンやエタンのホモカップリングにも応用できることが示されたことにより、本概念の一般性が示された。また金属触媒を合金化することでブレンド触媒を高活性化できたことも今後の発展につながる成果である．