The use of proton induced x-ray emission in the design and evaluation of catalysts

Abstract

In preparing a heterogeneous catalyst, it is usual practice to disperse one or more catalytic elements over a suitable high surface area support, such as porous alumina. It is very useful then to be able to monitor all the catalytic elements (and the trace impurities) within the crucial first few microns of the surface. The technique of proton-induced X-ray emission (PIXE) analysis is suited ideally to this purpose. The present work describes how it was used during the development of a new series of catalysts which were designed to be bonded to a special oxidation-resistant aluminium-containing steel, and used in vehicle exhaust emission control. In particular, we illustrate the use of PIXE in highlighting the relative resistances of different catalyst formulations to Pb poisoning.