Catalytic properties of perovskite-type automotive catalysts studied by dispersive XAFS

Matsumura, Daiju   ; Nishihata, Yasuo; Mizuki, Junichiro; Taniguchi, Masashi*; Uenishi, Mari*; Tanaka, Hirohisa*

In-situ and real-time structural transformations of perovskite-type automotive catalysts having a high catalytic activity during aging were observed by dispersive XAFS method. Alumina-based conventional catalysts were also observed for reference. The experiments were operated at the beamline of SPring-8 BL14B1. Just after dosing by oxygen or hydrogen, continuous XAFS spectra were measured at 20-50 Hz in order to reveal the local structural transformation of precious metals. For the Pd-perovskite catalyst, the slower response of structural transformation was observed than the alumina-based catalyst under the oxygen atmosphere. Similar results were observed in Pt-based catalyst. On the other hand, there were no clear differences between the perovskite-type and alumina-based catalyst of Rh.