(Invited) Field Trials Testing of Mixed Potential Electrochemical Hydrogen Safety Sensors at Commercial California Hydrogen Filling Stations

Abstract

Hydrogen safety sensors must meet specific performance requirements, mandated by the U.S. Department of Energy, for hydrogen fueling station monitoring. Here, we describe the longterm performance of two zirconia-based mixed potential electrochemical hydrogen gas sensors, developed specifically with a high sensitivity to hydrogen, low cross-sensitivity, chemical stability across operating temperatures, and fast response time. Over a two-year period, sensors with two different working electrodes-tin-doped indium oxide and strontium doped lanthanum chromite-were deployed at hydrogen filling stations in the Los Angeles area. The sensors exhibit high baseline stability and excellent correlation with logged filling/release events, making these materials good candidates for applications requiring long-life, drift-free baseline operation, in which sensor calibrations and replacements are prohibitive.

Editors’ Choice—Review—Recent Advances in Mixed Potential Sensors

“…102 The general technical targets for sensor operation described at the DOE workshop include sensitivity in the range of 0.1 to 10 vol% hydrogen by volume in air, less than 5% error in the full-scale reading, along with a response time less than one minute at 1% hydrogen by volume in air and less than one second at 4% as per the "Standard for Gas and Vapor Detectors and Sensors". [103][104][105] While a variety of electrochemical sensors have been reported over the years, a dearth of commercially available hydrogen sensors for meeting these specific needs at a suitable cost for wide-scale deployment has resulted in significant interest in recent years. 7,8,[106][107][108] A variety of sensors has been tested among which ITO|YSZ|Pt based sensors tend to give a high sensitivity, wide detection range, and durable performance.…”