Solid-state gas sensors for high temperature applications - a review

The development of high temperature gas sensors for industrial applications such as combustion processes is essential to improve energy efficiency and reduce toxic emissions. However, gas sensors operating at high temperatures up to 1000 degrees C typically encounter many challenging issues, such as thermal and long-term stability, sensitivity, reproducibility and selectivity. This feature article discusses a variety of solid-state gas sensors that can be operated at high temperatures above 600 degrees C. The basic working principles for each type of solid-state gas sensor are briefly introduced, including potentiometric, amperometric, resistive and impedancemetric sensors. The key results and discussions of previous studies on high temperature O-2, CO, HCs and NOx, sensors are also presented with emphasis on the development of suitable electrolytes and sensing materials with good thermal stability and sensing performance for such high temperature gas sensing applications. Finally, the challenges and scope for future development are discussed.