|About this Abstract
||Materials Science & Technology 2009
||Characterization and Modeling of Ceramic-Ceramic and Metal-Ceramic Interfaces
||Strong Interaction at Interfaces between Nanosized Metal Particles and Single Crystal Oxides in Model Catalysts
||Xiaoqing Pan, Obiefune K Ezekoye, Michael B Katz, Haiping Sun, Yi Zhang, George W Graham
|On-Site Speaker (Planned)
The interaction between metal particles and their oxide support can be strong enough to affect the reactivity of a catalyst system. Direct observation of metal-oxide interfaces with atomic resolution is a challenge and can only be achieved by cross sectional high-resolution transmission electron microscopy (HRTEM). With this approach, we found partial encapsulation of Pd particles by reduced ceria-zirconia in a model, single-crystal thin film auto catalyst. We also found that precious-metal particles (Pd, Pt, and Rh) can alternately dissolve into a perovskite support (CaTiO<sub>3</sub> and LaFeO<sub>3</sub>) as cations under oxidizing conditions and re-form as small metallic particles under reducing conditions. The effect of reduction and oxidation conditions on this interaction provides a qualitative explanation for a previously observed reversible reactivations in model powder three-way automotive exhaust-gas catalysts.