京都大学 · Energy
히사오 요시다 교수의 연구실은 태양광을 활용한 청정 에너지 변환 기술, 특히 수소 생산과 메탄 전환을 핵심으로 삼고 있습니다. 광촉매를 이용한 수증기 개질 반응(photocatalytic steam reforming of methane)과 생물유래 물질에서의 수소 생산에 대한 기초 및 응용 연구를 진행하며, 나노구조 촉매의 표면 화학적 특성과 산화 상태 분석에도 전문성을 기르고 있습니다. 특히 Pt, TiO₂, Cu 등 다양한 촉매 물질의 전자구조와 반응 메커니즘을 XANES 분석을 통해 정밀하게 규명하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Hydrogen, a clean energy carrier, should be produced from not the irreproducible fossil fuels but renewable resources. Currently hydrogen is mainly produced by the reforming of petroleum and natural gas at high temperature, which consumes huge energy. Thus, development of an alternative hydrogen production method is absolutely imperative to mitigate the environmental and energy issues. Photocatalytic hydrogen production from water and renewable resources is one of the attractive systems, since i
Various efforts have been carried out to convert methane to more useful chemicals and hydrogen. However, due to its high stability, high energy is usually consumed for its conversion, which still remains as a problem to be solved. Recently, photocatalysis has been proposed to be one of the answers to break the thermodynamic barrier. This tutorial review provides a brief history about developments in the methane conversion and specially highlights the developments in the photocatalytic conversion
Photocatalytic reaction of CH4 gas with H2O vapor was examined over Pt/TiO2 around room temperature (ca. 323 K) in a flow reactor. H2 and CO2 were the main products, and only trace amounts of C2H6 and CO were also observed. After an induction period, the molar ratio of H2 to CO2 in the outlet gas became close to 4. Thus, the main reaction is suggested as the equation CH4 + 2H2O(g) → 4H2 + CO2, which can be referred to as photocatalytic steam reforming of methane (photocatalytic SRM), where the p
Quantitative determination of platinum oxidation state on supported platinum catalyst was examined by using Pt LIII-edge XANES spectra. The nano-sized platinum particles on the support were partially oxidized under oxidative atmosphere. The atomic ratio of oxygen to platinum (O/Pt) for these particles could be determined by the amount of desorbed oxygen in He carrier (O2-TPD) during elevated temperature. On the other hand, the XANES spectrum of the platinum catalysts oxidized under each correspo
X-Ray absorption near-edge structure (XANES) spectra at the Cu L and K edges have been measured for a series of Cu(II) compounds to clarify the factor affecting the chemical shift in the XANES spectra. The energy positions of the 2p1/2 → 3d and 2p3/2 → 3d transition peaks in the Cu L2,3 XANES spectra and the 1s → 3d transition peak (pre-edge peak) in the Cu K-edge XANES spectra were strongly influenced by the chemical states of the Cu(II), i.e., the coordination geometries (tetrahedral, octahedr
