Dynamic structure of Pd metal fine particles during CO/NO catalytic reaction

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

Metal particles used in the catalytic reaction are made fine in order to spread the surface area. However, it is expected that the nanometer-sized metal particles show the original catalytic reaction which is different from that for the larger particles. In order to study the originality of the fine particles, detailed structure, shape and electronic informations will be required. Dispersive XAFS system enables us to observe the fine particles with high precise information. We used this method for the study of the changes in the Pd metal fine particles during CO/NO catalytic reaction. As a result, the expansion-contraction, aggregation-dispersion and oxidation-reduction changes in the Pd metal fine particles have been revealed by direct observation of dispersive XAFS method.