Selectivity-optimization of planar amperometric multi-electrode sensors: identification of O-2, NOx and combustible gases in exhausts at high temperatures

Experimental studies and numerical calculations have been performed to desc ribe and optimize the response of planar amperometric multi-electrode senso rs. These sensors may be used to detect simultaneously oxygen and NO or oxy gen and combustible components. The experimentally determined kinetics of t he electrode reaction and the gas phase diffusion have been included in the numerical calculation to optimize the geometry and the operation parameter s. An excellent agreement was obtained between modeling and experimental re sults. The sensor response signal depends strongly on the kinetics of the e lectrode reaction given by the materials, temperatures, and voltages as wel l as on the geometry of the cell. (C) 2000 Elsevier Science S.A. All rights reserved.