Development of novel operando catalytic reaction measurement system by atomic-level TEM observation and mass spectroscopy

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22102
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 28:Nano/micro science and related fields
• Research Institution: Nagoya University
• Principal Investigator: MUTO Shunsuke 名古屋大学, 未来材料・システム研究所, 教授 (20209985)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 金属微粒子触媒 / 高分解能電子顕微鏡 / 質量分析 / オペランド計測 / その場観察 / 反応活性点 / 自動車排気ガス

Outline of Final Research Achievements

The aim of the present study is to develop a new operando measurement system and thereby clarify the chemical reaction mechanisms by concurrent real-time atomic-level structural observation and detection of supply and product gases associated with the reactions.
A quadrupole mass spectrometer with gas chromatography attached was implemented to the Reaction Science High-Voltage TEM system equipped with a gas-environmental cell. For the application example, Rh fine metallic particles supported by ZrO2 were used as a model catalyst for purifying nitrogen oxides. The developed system was confirmed to actually detect the consumption of the supply gas and the product gas emission at the same time when the structural changes of particle surfaces were observed in atomic resolution with increasing temperature.

Free Research Field

ナノ材料物性解析

Academic Significance and Societal Importance of the Research Achievements

現在，S/TEM観察技術において最もホットな分野の一つが実際のデバイスの実動作条件を電子顕微鏡（TEM）内で再現して高空間分解能でそのダイナミクスを捉える「オペランド測定」である．TEM技術は，実空間での高い空間分解能において材料科学分野の他の実験手法を圧倒するが，標準分析装置の元素分析感度は1原子%程度である．そこで，ガス環境セルを設置した本学反応科学超高圧TEMに質量分析装置を設置し，実際に原子レベルでの構造変化観察と同時に微量反応生成ガスの検出に成功した．おそらく世界で初めて自動車排気ガス浄化触媒反応のダイナミクスを画像とスペクトルで同時に捉えることができ、反応機構の解明に寄与した．