In-situ TEM Observation of Structural Changes of Carbon Catalysts

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05248
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 36020:Energy-related chemistry
• Research Institution: National Institute for Materials Science
• Principal Investigator: HASHIMOTO Ayako 国立研究開発法人物質・材料研究機構, マテリアル基盤研究センター, 主幹研究員 (30327689)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 透過型電子顕微鏡 / 触媒 / 炭素

Outline of Final Research Achievements

In this study, we aimed to reveal the structural changes of carbon catalysts in the thermo-catalytic process by using transmission electron microscopy (TEM), which is attracting attention as one of clean hydrogen production methods.
Our developed differential pumping-type gas environmental heating TEM specimen holder allow us to observe a specimen in gas phase with ~20 Pa pressure at ~1000°C. The ex-situ experiments were performed with a vacuum chamber, and the structural changes of carbon black were captured by observing the same regions before and after heating in methane gas. Graphitization was observed and progressed with reaction time. However, a balloon-like graphene layers were found to form on the surface of some carbon blacks. For comparison, in-situ observations were also performed for the Ni nanoparticle catalyst.

Free Research Field

透過型電子顕微鏡

Academic Significance and Societal Importance of the Research Achievements

現在、水素製造には、主に化石燃料を水蒸気改質させる方法がとられている。しかしながら、よりクリーンなエネルギーを求めて、化石燃料に替わる素材、水蒸気改質法に替わる生成方法が国内外を問わず、盛んに研究・開発されている。炭素触媒を用いた熱触媒法による水素生成はその一つである。
炭素触媒の水素生成についても多数の研究がされているが、その多くは触媒特性評価が中心となっており、構造評価について行っている例は少ない。そこで、本研究は構造変化をTEMで捉えることを目的とし、炭素触媒の反応過程や劣化過程に関する知見を深める。