Electrical In Situ Characterization of Three-Way Catalyst Coatings

With a novel sensor, the electrical characteristics of a catalytically active three way catalyst coating can be gauged directly and evaluated. Therefore, in initial tests, several sensors that measure the electrical properties of the washcoat were mounted in a catalytic converter and the electrical resistances were measured. The sensors primarily provide information on the oxidation state of the oxygen storage compounds in the coating. It is shown that the sensor devices have fast response times and probably even react more sensitive to small changes in oxygen partial pressure than lambda-probes.