The Analysis of Meta lCatalyst Nanoparticle by Atom Probe Tomography

Nano alloys based on platinum form the basis for automobile exhaust catalyst, one of the most successful and important families of heterogeneous catalysts used in industry today. In this study, the structure of Pt-Pd catalyst is analyzed by atom probe tomography (APT). APT which has high spatial resolution and high detection sensitivity with single atomic level is widely used in the world in order to evaluate atomic structure of metals and semiconductor materials as typified by field effect transistor. The transformation of catalyst surface composition was observed by several thermal and environmental conditions in order to discuss the deterioration of catalyst. To observe the existence of catalytic reaction under APT condition, the field evaporated ions which originated from CxHy thin film on Pt-Pd or W needle were compared. In the result of this study, the transformation of composition at surface micro region occurs by thermal treatment of Pt-Pd alloy.