PTRF X-ray absorption fine structure as a new technique for catalyst characterization

✍ Scribed by W.-J. Chun; M. Shirai; K. Tomishige; K. Asakura; Y. Iwasawa

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 709 KB
• Volume: 107
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(95)00163-8

✦ Synopsis

A chamber for observation in situ of polarized total-reflection fluorescence extended X-ray absorption fine structure (PTRF-XAFS) spectra was constructed, which makes it possible to measure the PTRF-XAFS spectra in situ under preparation, treatment, and reaction conditions from high vacuum( 1 × 10 9 Pa) to high pressure( 1 X 105 Pa) and from low temperature( 100 K) to high temperature( 800 K). The PTRF-XAFS technique can provide information on asymmetric or anisotropic structure of active metal and metal-oxide sites supported on single crystal substrates as models for supported catalysts, by measuring bondings of supported species in two or three different directions parallel and perpendicular to the surface independently. Typical EXAFS and XANES spectra for Cu 2+/a-SiO2 (000l), CoOx/o!-Al203 (0001), [Pt]a/ff-Al203 (0001), and V2Os/ZrO2 (100) taken by the PTRF-XAFS chamber are discussed in relation to their catalytic properties.