Development and testing of a miniaturized hydrogen safety sensor prototype

Abstract

In this article, the development and testing of an electrochemical hydrogen (H 2) sensor prototype based on ‘indium tin oxide (ITO)/yttria-stabilized zirconia (YSZ)/platinum (Pt)’ configuration is detailed. The device fabricated on an alumina substrate integrates a resistive Pt heater to achieve precise control of operating temperature while minimizing heterogeneous catalysis. Targeting fuel cell powered automotive applications, the safety sensor was subjected to interference studies, temperature cycling, operating temperature variations, and long-term testing over 2000 h. The sensor responded in real-time to varying concentrations of H 2 (1000–20,000 ppm). Among the interference gases tested such as nitric oxide (NO), nitrogen dioxide (NO 2), ammonia (NH 3), carbon monoxide (CO), and propylene (C 3H 6), the sensor showed cross-sensitivity to C 3H 6. Analyzing the overall device performance over 2000 h of testing for 5000 ppm of H 2, (a) the sensitivity varied between 0.135 and 0.167 V, (b) the baseline signal ranged from 0 to 0.04 V, and (c) the response rise time fluctuated between 3 and 7 s. The salient features of the H 2 sensor prototype developed by Los Alamos National Laboratory (LANL) are (a) the low power consumption, (b) compactness to fit into critical areas of application, (c) simple operation, (d) fast response, (e) a direct voltage read-out circumventing the need for any additional conditioning circuitry and (f) conducive to commercialization.