Presentation Information
[3F15]Detection of methane oxidation using platinum-group metal oxide nanosheets.
*Naoto Ochi1, Takanori Koitaya2, Yoshiaki Ishihara3, Daisuke Takimoto4, Wataru Sugimoto5,6, Susumu Yamamoto7,8, Iwao Matsuda9, Jun Yoshinobu9, Ryo Nouchi1,3 (1. Department of Physics and Electronics, Osaka Metropolitan University, 2. Department of Chemistry, Kyoto University, 3. Department of Physics and Electronics, Osaka Prefecture University, 4. Faculty of Science, University of the Ryukyus, 5. Research Initiative for Supra-Materials (RISM), Shinshu University, 6. Faculty of Textile Science and Technology, Shinshu University, 7. International Center for Synchrotron Radiation Innovation Smart, Tohoku University, 8. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 9. Institute for Solid State Physics, The University of Tokyo)
Methane, a promising source of value-added chemicals, is typically challenging to oxidize owing to its stable C-H bonds. However, recent findings have shown methane activation on IrO2(110) surfaces even below room temperature, which is explained by its strong bonding with CH3 fragments. Our study focuses on methane oxidation using nanosheets of several platinum group metal oxides (IrO2, RuO2, and PtO2). Insulating PtO2 demonstrated significant resistance changes owing to reduction during methane oxidation, unlike metallic IrO2 and RuO2. Ambient-pressure X-ray photoelectron spectroscopy measurements showed that PtO2 was most significantly reduced by methane at room temperature. Raman scattering spectroscopy confirmed the presence of amorphous carbon, one of products of the methane oxidation reaction, with the largest signal obtained from PtO2 after methane exposure. These results consistently reveal the higher methane activation ability of PtO2 than IrO2 in the form of nanosheets.