Dosimeter-Type NO[subscript x] Sensing Properties of KMnO[subscript 4] and Its Electrical Conductivity during Temperature Programmed Desorption

An impedimetric NO[subscript x] dosimeter based on the NO[subscript x] sorption material KMnO[subscript 4] is proposed. In addition to its application as a low level NO[subscript x] dosimeter, KMnO[subscript 4] shows potential as a precious metal free lean NO[subscript x] trap material (LNT) for NO[...

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Bibliographic Details
Main Authors: Groß, Andrea, Kremling, Michael, Marr, Isabella, Kubinski, David, Visser, Jacobus, Moos, Ralf, Tuller, Harry L.
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: MDPI AG 2014
Online Access:http://hdl.handle.net/1721.1/92286
https://orcid.org/0000-0001-8339-3222
Description
Summary:An impedimetric NO[subscript x] dosimeter based on the NO[subscript x] sorption material KMnO[subscript 4] is proposed. In addition to its application as a low level NO[subscript x] dosimeter, KMnO[subscript 4] shows potential as a precious metal free lean NO[subscript x] trap material (LNT) for NO[subscript x] storage catalysts (NSC) enabling electrical in-situ diagnostics. With this dosimeter, low levels of NO and NO[subscript 2] exposure can be detected electrically as instantaneous values at 380 °C by progressive NO[subscript x] accumulation in the KMnO[subscript 4] based sensitive layer. The linear NO[subscript x] sensing characteristics are recovered periodically by heating to 650 °C or switching to rich atmospheres. Further insight into the NO[subscript x] sorption-dependent conductivity of the KMnO[subscript 4]-based material is obtained by the novel eTPD method that combines electrical characterization with classical temperature programmed desorption (TPD). The NO[subscript x] loading amount increases proportionally to the NO[subscript x] exposure time at sorption temperature. The cumulated NO[subscript x] exposure, as well as the corresponding NO[subscript x] loading state, can be detected linearly by electrical means in two modes: (1) time-continuously during the sorption interval including NO[subscript x] concentration information from the signal derivative or (2) during the short-term thermal NO[subscript x] release.