Theoretical study of structure-activity relationship for soft Lewis acidity of noble metal nanocluster catalysts

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05752
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Osaka University
• Principal Investigator: Okumura Mitsutaka 大阪大学, 理学研究科, 教授 (40356712)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ソフトルイス酸的触媒活性 / 量子化学 / 触媒化学 / 異性化反応 / 反応機構 / ヘテロ接合

Outline of Final Research Achievements

The reaction mechanisms of the soft Lewis acid catalytic activity over noble metal clusters and noble metal supported cluster catalysts were theoretically examined.
The isomerization of 3,4-DABE in isolated clusters was investigated by changing the cluster size and their charges. The activation barrier for the catalytic reaction was generally lower in positively charged clusters than neutral clusters. In particular, theoretical calculations revealed that there is a clear correlation that the activation barrier decreases as the magnitude of the positive charge of the metal atom of the adsorption site increases. When the clusters are supported by metal oxides, the activation barrier at the interfacial noble metal atom sites is relatively low even in the neutral model system.

Free Research Field

量子化学

Academic Significance and Societal Importance of the Research Achievements

触媒化学における貴金属と金属酸化物などの間のヘテロ接合効果は大変興味深い題材であるとともに、この現象を解明することは触媒化学分野における触媒機能発現機構解明に大変大きな示唆を与えるものである。そこで、我々は従来の均一触媒では数多く報告されていたソフトルイス酸的な触媒活性が、なぜ担持触媒ではあまり報告されてこなかったかとソフトルイス酸的触媒活性の発現機構を理論的に明確にした。このことは、貴金属のヘテロ接合界面に対する一般的な概念構築に重要な示唆を与えるものであった。