A review of high-temperature solid-state ammonia sensors

Being widely used as a toxic gas in chemical production, medical applications, agricultural production and automotive industry, ammonia not only poses a great threat to atmospheric pollution when exposed to the atmosphere, but also can cause damage to the life safety of animals or humans. To ensure the safe and accurate use of ammonia in various fields, especially in selective catalytic reduction (SCR) systems for automobiles and boilers, a high-performance ammonia sensor is necessary. Solid-state electrolyte sensors are deemed to be excellent performers for high-temperature environments in automobiles and boilers. We have been looking at how ammonia sensing has evolved over time, and it is clear that mixed potential sensors have a lot to offer high-temperature ammonia detection. In this review, the classification, sensing mechanism, materials and development trends of solid-state ammonia sensors are detailed, and it also discusses the current sensing performance of solid-state ammonia sensors and the way forward for their optimization. Although the performance of present ammonia sensors has been improved by the thorough research of scientists, there remains more room for development in sensitivity, selectivity and response/recovery time. Improving the three-phase boundary, increasing the active sites and reducing the cross-sensitivity will be part of the future development trend of ammonia sensors. [GRAPHICS] .