Environmental catalyst design based on surface electron spin control

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02518
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 27030:Catalyst and resource chemical process-related
• Research Institution: Kumamoto University
• Principal Investigator: Yoshida Hiroshi 熊本大学, 大学院先端科学研究部(工), 助教 (40722426)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: NO還元 / 三元触媒 / 貴金属代替 / 電子的相互作用

Outline of Final Research Achievements

Various alloy nanoparticles and composite metal oxide supported catalysts composed of non-noble metals were prepared and their three-way catalytic activities were investigated. The effects of composition, oxidation state and electronic interactions on the NO reduction activity were also discussed. The Fe-Ni alloy nanoparticles formed on the Al2O3 surface showed excellent NO reduction activity in the three-way catalytic reaction, suggesting that alloying with Ni improved the stability of Fe in the lower oxidation state, thereby enhancing the NO reduction activity. In addition, pseudo-spinel type (NiCu)Al2O4 was formed on the catalyst surface of Ni-Cu/Al2O3 after thermal aging at high temperature. It was found that the tetrahedrally coordinated Cu with higher electron density due to electron donation from octahedrally coordinated Ni played a key role in enhancing the NO reduction activity.

Free Research Field

触媒化学

Academic Significance and Societal Importance of the Research Achievements

内燃機関の排ガス浄化は人類にとって重要課題であり、O2存在下でのNOx浄化を実現する触媒開発およびその作用機構解明は産業面のみならず学術的に重要である。本研究では白金族元素を用いることなく汎用元素の酸化状態や配位環境の制御により高いNO還元活性を発現するいくつかの固体触媒材料開発に成功したが、これまで単一金属としては活性を示さなかったFeやNiが複合化することで活性発現すること、また異種金属との電子的相互作用が触媒機能を加速する効果は今後のNOx還元触媒開発における重要知見である。中でも複合酸化物によるNO還元はO2存在下でのNOx還元を実現する上で有用であり、本触媒の工業利用が期待される。