RF-probing of Automotive Catalysts

Titelangaben

Reiß, Sebastian ; Moos, Ralf ; Wedemann, Marion ; Spörl, Matthias ; Nerowski, Alexander ; Fischerauer, Gerhard:
RF-probing of Automotive Catalysts.
In: Proceedings SENSOR 2009. - Wunstorf : AMA Verband für Sensorik und Messtechnik e.V. , 2009 . - S. 113-116
ISBN N 978-3-9810993-5-5
DOI: https://doi.org/10.5162/sensor09/v2/b7.1

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Abstract

In order to meet the strict emission regulations, gasoline operated vehicles are equipped with three-way catalysts (TWC) and lambda sensors are applied to control the exhaust gas aftertreatment system. Since the TWC achieves maximum conversion of hydrocarbons, carbon monoxide, and nitrogen oxides at λ ≈ 1, λ is measured by lambda-probes upstream and downstream of the catalyst and is readjusted if required (λ: normalized air-to-fuel ratio). This leads to an oscillating air-to-fuel-ratio that is damped by oxygen storage components in the washcoat of the TWC (ceria-zirconia mixed oxides). These ceria-based materials store oxygen under lean atmospheres (λ > 1) and release oxygen under rich conditions (λ < 1).

In the present contribution, aspects of a novel approach to determine the oxygen loading of a TWC by a contactless measurement and in-situ with the help of radio frequency (RF) without lambda-probes is presented.