Study on redispersion for regeneration of environmental catalysts

Research Project

Project/Area Number	18K05201
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 34030:Green sustainable chemistry and environmental chemistry-related
Research Institution	Osaka University
Principal Investigator	Kamiuchi Naoto 大阪大学, 産業科学研究所, 助教 (00626012)
Project Period (FY)	2018-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000) Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2018: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Keywords	環境触媒 / 金属酸化物担持貴金属触媒 / 再分散 / 再活性化 / ナノ構造 / 環境制御型TEM / その場観察 / 環境制御型透過電子顕微鏡
Outline of Final Research Achievements	In the metal nanoparticle catalyst used as an environmental catalyst, redispersion phenomenon is significant because it can lead to the recovery of catalytic performance. In this work, the conditions for redispersion were searched, and the mechanism of the redispersion phenomenon was carefully studied using an environmental TEM. In the rhodium catalyst supported on tin oxide (Rh/SnO2), it is noteworthy that the performance of the degraded catalyst for CO oxidation reaction is partially reactivated by the reoxidation treatment at 400 degree Celsius. Furthermore, the process of the redispersion of rhodium species on the surface of SnO2 was clarified in situ by environmental TEM observation.
Academic Significance and Societal Importance of the Research Achievements	金属ナノ粒子触媒の再分散現象は、性能劣化した触媒を再活性化させる方法の一つであり、貴重な資源である貴金属の有効活用にも繋がるため、実用上極めて重要なナノ構造変化である。しかし、再分散現象の発現メカニズムは十分に解明されていない。本研究では、有害ガスである一酸化炭素を無害化する反応 (CO酸化反応) に高い性能を示すロジウム触媒に着目し、酸化還元処理により引き起こされる再分散現象を、その場観察により明らかにした。本研究課題で得られた成果は、様々な金属ナノ粒子触媒の再活性化の実現に繋がると期待される。