Selective detection of NO using the perovskite-type oxide LaMO3 (M = Cr, Mn, Fe, Co, and Ni) as the electrode material for yttrium-stabilized zirconia-based electrochemical sensors

Abstract

Yttrium-stabilized zirconia-based electrochemical gas sensors have good application prospects in NO high-temperature detection systems due to their stability under extreme conditions. In this study, an LaMO₃ (M: Cr, Mn, Fe, Co, and Ni) perovskite was prepared using the sol–gel method as the electrode material for an yttrium-stabilized zirconia-based electrochemical sensor for the selective detection of NO. The influence of M-site metals on the electrode performance was revealed through various experimental characterization studies and first-principles calculations. The results indicate that the response values of the different M-site metal perovskites can be arranged in the following order: LaCrO₃ > LaMnO₃ > LaFeO₃ > LaNiO₃ > LaCoO₃. Among them, LaCrO₃ exhibits a response value of −64.11 mV to 100 ppm NO, with high sensitivity (−41.19 mV per decade) and high selectivity. Further research has demonstrated that the number of oxygen vacancies and response values in these perovskite materials follow the same order. Electrochemical impedance spectroscopy indicated that LaCrO₃ exhibited the lowest polarization resistance, and that these changes promoted the adsorption and reaction of NO on the electrode. Finally, the mechanism of NO adsorption on the LaCrO₃ surface was revealed using density functional theory calculations. This study not only provides a new approach for selecting high-performance electrode materials but also reveals the fundamental impact of M-site metals on the performance of perovskites.