Development of platinum-free oxygen reduction catalysts based on oxide nanosheets with tailored two-dimensional active sites

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K19187
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Inorganic materials chemistry, Energy-related chemistry, and related fields
• Research Institution: National Institute for Materials Science
• Principal Investigator: TANIGUCHI Takaaki 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 主任研究員 (50583415)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: 酸素還元触媒 / ナノシート / ドーピング / 燃料電池

Outline of Final Research Achievements

We aimed to develop a high-performance oxygen reduction catalyst based on oxide nanosheets. In the case of titanium oxide nanosheets, Co/N co-doped layered titanium oxides with enhanced ferromagnetism were synthesized. They were successfully exfoliated into nanosheets. We also synthesized nitrogen doped KCa2NaNb5O19 with electrical conductivity, while the material were not exfoliated. The RuO2 nanosheet catalysts doped with Co and Fe were also successfully synthesized. On the other hand, no high oxygen reduction activity under acidic conditions was found in these new materials. Therefore, to return to the basics of the reaction field design, we additionally focused on molybdenum sulfide sheets. As a result,the enhancement of the catalytic activity by the interfacial electric field was discovered.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

酸化物ナノシートの多くは絶縁体であるが、電子伝導化技術が開発されれば、その用途は大きく広がるはずである。本研究は、酸化物ナノシートに導電性と活性点を付与することで、酸性下で機能する酸素還元触媒の開発に挑んだ。結果として高機能触媒を開発するに至らなかったが、アニオン/カチオン共ドープ型酸化チタンナノシート等、新規ナノシート合成を通し、これまでにない高導電性や強磁性が獲得された。また、MoS2では、単層ナノシートにおいて、著しく触媒活性が増強することを見出した。このように、本研究を通し、ナノシートの組成、構造、物性制御技術、触媒活性化メカニズムの理解について進展させることができた。