EELS INVESTIGATION OF PD THIN-FILM GROWTH ON MB SUBSTRATE

Using multi-component catalysts offers the possibility to optimize the individual reaction steps. In the last decades, great attention has b een focused on bimetallic systems, representing the next step from mon ometallic catalysts to multi-component ones. However, this approach re quires detailed knowledge of both the influence of individual componen ts and their mutual cooperation. In the study of these factors it is a dvantageous to use ultra-high vacuum conditions where well-defined-met al surfaces, so-called model catalysts, can be prepared and characteri zed by modern surface-science techniques. The Pd/Nb model catalysts we re prepared by depositing a small amount of palladium on polycrystalli ne niobium substrates. The film growth was investigated via variations of intensity ratio of excited Pd and Nb plasmons. It has been found t hat Pd-Nb interface was formed by a continuous Pd layer growing on Nb substrate. (C) 1998 Elsevier Science Ltd. All rights reserved.