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This study focuses on the durability characteristics of the electrically heated converter (EHC). The basis of these investigations was the development of tests specific to the electrical heating function. This paper summarizes tests used to develop dielectric barriers and to confirm the durability of the final material used on W.R. Grace & Co.-CONN., Cam-E-Lite™ EHC designs. The properties evaluated include critical cohesion and adhesion characteristics between the coatings and metal supports as well as the thermal stability of the coatings in high temperature environments. Results are presented to address the durability of dielectric barriers applied to individual heater leaves or incorporated into functional EHCs.

The use of cerium oxide as an oxygen storage component in automotive three-way catalysis has been well established. More recently the need to thermally stabilize these materials against deactivation at higher temperatures has focused attention on doping of the ceria with a wide range of metal oxides. The role of these dopants in the stabilization mechanisms for ceria is not completely understood as they must perform the complex role of sintering inhibitor while promoting oxygen storage and release. The scattering of pulsed neutrons produced by a spallation source coupled with the Fourier analysis provides a powerful method to characterize the local atomic structure of complex systems such as mixed oxides. We demonstrate that by using this method it is possible to obtain valuable information on the local atomic structure of the CeO2/ZrO2 catalyst support that cannot be attained by the conventional diffraction methods.