PNNL

Abstract

In this brief proceedings paper, we describe a continuing program aimed at defining and understanding the reaction kinetics over well defined metal single crystal catalysts under conditions of temperature and pressure comparable to those encountered in automotive exhaust. By studying such well-defined model catalysts, we are able to isolate the activity of the noble metal component of the catalyst free from complicating factors such as metal particle size and catalyst support efforts. Because single crystals have well-defined surface structures, surface areas, and no support effects, they are ideal for activity comparisons between metal surfaces with varying geometric structures. A particular focus of our current studies is on how the catalytic chemistry is effected by the oxygen uptake, storage, and release processes carried out by the oxygen storage material. For these latter studies, we have prepared and characterized a number of model, single crystal thin films of ceria with and without Zr-doping.