Pd/In2O3-based bilayer H2 sensor with high resistance to silicone toxicity and ultra-fast response

Hydrogen sensors are easily deactivated by hexamethyldisiloxane (HMDSO) poisoning. Moreover, the existing anti-poisoning strategies can also damage the overall sensing per-formance of these hydrogen sensors. Therefore, a new bilayer design with a Pd/In2O3 sensitive layer and an In2O3/Al2O3 catalytic filter layer is proposed to avoid the deactivation of hydrogen sensors. The In2O3/Al2O3 layer helps in hindering HMDSO and its decompo-sition products from reaching the Pd/In2O3 layer. The H2 response of the sensors is enhanced due to the small size of In2O3 and the electronic sensitization of Pd. As a result, the bilayer sensors exhibit high response (Ra/Rg = 53) and ultra-fast response time (1 s) towards 3000 ppm H2 at 365 degrees C. The resistance and the H2 response of the bilayer sensors are almost unchanged after 40 min of 10 ppm HDMSO poisoning. In this paper, the mechanism of resistance against silicone poisoning and the H2 response of the bilayer sensors are discussed from the separation of sensing and catalytic filtration reactions to the behavior of adsorbed oxygen.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.