Abstract
This work focuses on use of the electronically-conducting oxide La 0.85Sr0.15CrO3 (LSC) in solid electrolyte-based NOx sensing elements intended for operation at T ∼650 °C. Two different investigations are described, in the first LSC was used as a direct substitute for Pt. The substitution led to decreased sensitivity to NO2 and an enhancement of the NO response, although the NO 2 response was still much larger in magnitude and opposite in sign. Fabrication and evaluation of sensing elements with co-planar LSC and Pt electrodes comprised the second investigation. The measured NOx sensing performance of these elements was commensurate with that of the elements fabricated in the first phase of the investigation (e.g., 450 ppmv NO2 in 7 vol% O2 produced ∼50 mV at 600 °C) and the response/recovery times for NO2 sensing were improved. The results indicate that LSC could be useful in these types of sensing elements, both as a substitute for, and in combination with, Pt.
| Original language | English |
|---|---|
| Pages (from-to) | 758-765 |
| Number of pages | 8 |
| Journal | Sensors and Actuators, B: Chemical |
| Volume | 106 |
| Issue number | 2 |
| DOIs | |
| State | Published - May 13 2005 |
Funding
The authors wish to thank C.A. Walls for fabricating the YSZ substrates, B.L. Armstrong for formulating and producing the screen-printing inks, S.B. Waters for assistance with electron microscopy, and D. Kubinski and R. Soltis of Ford Scientific Research Laboratories (Dearborn, MI) for consultation in automotive sensing requirements. Oak Ridge National Laboratory is operated by UT-Battelle, LLC for the U.S. Department of Energy under contract DE-AC05-00OR22725.
Keywords
- Gas sensors
- Lanthanum strontium chromite
- Nitrogen dioxide
- Nitrogen monoxide