Cubic Bi2O3-Based Electrochemical Nitric Oxide Sensor Using Double Perovskite Oxide Electrodes

For achieving a sustainable energy future, energy consumption through renewable sources needs to be maximized and greenhouse emissions should be radically reduced. Automotive exhausts sharing the largest global NO X emissions must meet regulated standards by after-treatment systems (ATS) equipped with smart electronic feedback loops through on-board NO X monitoring. Herein, we demonstrate an efficient (Dy, W) co-doped Bi 2 O 3 -based electrochemical sensing architecture equipped with Ln 2 NiMnO 6 double perovskite oxides (DPOs) as electrode materials for selective nitric oxides (NO) detection. The sensor configuration facilitates operation in a wide temperature range (325 °C–500 °C) with high sensitivity of 50 mV/decade, a response time below 60 sec. and detection abilities as low as 200 ppb. While investigating the impact of rare-Earth cations, a predominant Ni 3+ –O–Mn 3+ interaction and acquisition of optimal e g 1 electron configuration of transition metal atoms in La 2 NiMnO 6 was found responsible for improved electrocatalytic and redox chemical activity that substantiates the sensing behavior. The study carefully scrutinizes the sensing mechanism to abide by the mixed-potential model. Moreover, the durability assessed over a month of operation supported the applicability of presented sensing elements in on-board NO X monitoring systems.