2019 Fiscal Year Final Research Report
Observation and control of transition state for catalytic reactions by using X-ray absorption spectroscopy
| Project/Area Number |
17KT0007
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Multi-year Fund |
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| Section | 特設分野 |
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| Research Field |
Transition State Control
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Project Period (FY) |
2017-07-18 – 2020-03-31
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| Keywords | X線吸収分光 / 赤外吸収分光 / オペランド分光 / CO2の水素化 |
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| Outline of Final Research Achievements |
We elucidated the active sites for unfavorable CH4 formation over Al2O3-supported Pt catalyst during hydrogenation of CO2 at ambient pressure, by using a combination of X-ray absorption spectroscopy (XAS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) with product analysis (operando XAS-DRIFTS). Bicarbonate species are formed on the Al2O3 surface upon adsorption of CO2 at the surface hydroxyl groups of Al2O3. Those bicarbonate species are hydrogenated toward CO by hydrogen spillover from Pt surface as the dissociation sites of H2. The combined data of XAS and DRIFTS revealed that CO species co-adsorbed with H on the perimeter Pt sites at the interface between Pt particles and Al2O3 surface, and then further hydrogenation of those CO species led to the CH4 formation.
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| Free Research Field |
触媒化学
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| Academic Significance and Societal Importance of the Research Achievements |
不均一系触媒反応における反応機構を「基質や生成物などの分子の振る舞い」に加えて「触媒自体の構造変化」から速度論的に解釈するため，兵庫県佐用市光都に位置する大型放射光施設SPring-8内のBL01B1にX線吸収スペクトルと赤外吸収スペクトルを同時に測定しながら，触媒反応を観察することができるシステムを構築した．このシステムを用いてAl2O3担持Pt触媒上でのCO2の水素化の反応機構解析を行い，詳細な反応メカニズムを提案した．
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