2002 年 23 巻 4 号 p. 215-223
Recently in-situ XAFS analysis of the catalysts under reaction conditions has widely been performed together with synchrotron radiation light sources of the 2nd−3rd generation. In some cases this method requires time-resolving analytical techniques such as DXAFS and QXAFS. In addition, design of the in-situ cell is crucial for obtaining spectra which properly reflect the structures of the catalysts under reaction conditions. Two kinds of in-situ cells designed for experiments under high-pressure conditions are presented. Four of recent works are reviewed: Observation of Mo suboxide species during reduction of MoO3, Cu+ species formed in Cu-ZSM-5 during reduction process, structural change of Cu metal particles on Cu/ZnO under various reaction conditions, and Rh species during CO2 hydrogenation. Intermediate species appearing in the course of chemical reactions have very short lives, therefore continuous observation of surface species by in-situ method is indispensable for detection of such species. Moreover, the in-situ method is the only way to obtain the structure of catalysts under the reaction conditions.