Determination of nitrous oxide concentration using a solid-electrolyte amperometric sensor

Abstract

Herein, are presented the results of the investigation of an electrochemical sensor, based on oxygen-conducting yttria stabilized zirconia (YSZ) solid-state electrolyte, used for the determination of nitrous oxide in gas mixtures. For this purpose, a solid-electrolyte amperometric sensor with a capillary, serving as a diffusion barrier, is fabricated and tested. The experiments are carried out using the following binary gas mixtures: i) nitrous oxide – nitrogen, ii) nitrous oxide – oxygen, and iii) nitrous oxide – air, in a wide range of nitrous oxide concentration values at a sensor working temperature of 700 °C, which ensures the complete decomposition of nitrous oxide into oxygen and nitrogen. The volt-ampere dependencies for the different gas compositions are thoroughly investigated. Moreover, on the basis of the obtained results, the effect of nitrous oxide concentration on the sensor’s limiting current is also examined. These plots allow determining the nitrous oxide concentration in each one of the above mentioned gas mixtures. The sensor exhibits good reproducibility and high stability. The obtained results testify that the proposed method is very promising, efficient, simple and not expensive, having good dynamic characteristics of analysis with a transient time of about 1 min, acceptable for practical feasibility.