NO Detection By Cyclic Voltammetry with Platinum Electrodes on YSZ

摘要

Solid electrolyte sensors (SES) based on yttria stabilized zirconia (YSZ) can be used to detect traces of other components in inert gases such as Ar or N_2. The O~(2-)-conducting solid electrolyte YSZ is thermodynamically highly stable and can be operated at high temperatures with stationary (potentiometry, amperometry) or dynamic methods (pulse polarization, cyclovoltammetry (CV)). In the stationary mode, the selectivity of such sensors is limited to an extend that it is usually not possible to distinguish between individual gas components. In contrast to that, dynamic methods allow a significantly increased selectivity by using different rates of electrode reactions of the individual components in order to detect them independently in a gas mixture. Dynamic electrochemical methods have been successfully used in liquids for many decades, and preliminary investigations on solid electrolyte gas sensors also show that such methods can be used to measure the concentrations of several redox-active gases, for example, oxygen and carbon monoxide. The commercial solid electrolyte sensor used in this work was previously successfully tested to measure selectively different gases such as hydrogen, oxygen and water vapor in nitrogen by using CV. In this work, these studies will be continued to investigate the ability of CV for selective detection of nitrogen oxides (NO_x) and to elucidate the mechanisms of signal formation.