Editors' Choice—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 long-term performance of two zirconia-based mixed potential electrochemical hydrogen gas sensors, developed specifically with a high sensitivity to hydrogen, low cross-sensitivity, and fast response time. Over a two-year period, sensors with tin-doped indium oxide and strontium doped lanthanum chromite electrodes were deployed at two stations in four field trials tests conducted in Los Angeles. The sensors documented the existence of hydrogen plumes ranging in concentration from 100 to as high as 2700 ppm in the area surrounding the dispenser, consistent with depressurization from 700 bar following vehicle refueling. As expected, the hydrogen concentration reported by the mixed potential sensors was influenced by wind direction. Baseline stability testing at a Chino, CA station showed no measureable baseline drift throughout 206 days of uninterrupted data acquisition. The high baseline stability, excellent correlation with logged fueling/depressurization events, and absence of false alarms suggest that the zirconia-based mixed potential sensor platform is a good candidate for protecting hydrogen infrastructure where frequent calibrations or sensor replacement to reduce the false alarm frequency have been shown to be cost prohibitive.

Electrochemical Response of Mixed Conducting Perovskite Enables Low-Cost High-Efficiency Hydrogen Sensing

“…Gas sensors are vital for numerous applications in public and industrial safety, exhaust control, environmental monitoring, and disease diagnosis. − Electrochemical potentiometric gas sensors have attracted much attention owing to simplicity, wide concentration range, high stability, and potential for miniaturization and integration. Classical Nernst-type sensors have been successfully commercialized but are applicable only for a limited number of gases due to a lack of suitable electrode/electrolyte materials. − In contrast, the emerging non-Nernstian sensors are flexible in choice of materials and usable for numerous reactive gases. − Nevertheless, the sensing mechanism remains elusive, while rational design of highly sensitive and selective sensors has been a challenge. The sensor response is the difference between responses of the sensing electrode (SE) and counter electrode (CE), and hence both electrodes could play a crucial role.…”

Amperometric Hydrogen Sensor Based on Solid Polymer Electrolyte and Titanium Foam Electrode

“…Furthermore, it is necessary to use low-cost hydrogen sensors to rapidly detect trace hydrogen (ppm level) for the popularization of safety detection of LIBs. 18 , 19 …”

“…Electrochemical gas sensors, especially amperometric gas sensors, are widely used in trace gas detection due to their advantages of high sensitivity, low manufacturing cost, environmental protection, low power consumption, and easy integration. − At the same time, combined with the international standards of hydrogen detection and the monitoring requirements of LIBs, − stricter requirements are put forward for the sensitivity, response speed, and anti-interference ability of hydrogen detection. Furthermore, it is necessary to use low-cost hydrogen sensors to rapidly detect trace hydrogen (ppm level) for the popularization of safety detection of LIBs. , …”

Field Testing of a Mixed Potential IoT Sensor Platform for Methane Quantification

“…MPES sensor arrays have previously sensed hydrocarbons, NO X , NH 3 , H 2 , and CH 4 at ∼10-5000 ppm level concentrations. [31][32][33][34][35][36] These previous studies demonstrated that Indium Tin Oxide (ITO) measured vs Pt was an effective sensor for CH 4 , La 0.87 Sr 0.13 CrO 3 vs Pt was an effective sensor for heavier hydrocarbons such as ethane and propane as well as NO x , and Au vs Pt was an effective sensor for species including CO and NH 3 . NH 3 in particular is expected to be used as a fingerprint for agriculturally generated methane.…”

“…The bulk of the literature on mixed potential sensors has been in laboratory conditions where the sensors were exposed to well controlled concentrations of test gases. Real world tests for MPES devices have been reported by Brosha et al on H 2 sensors at filling stations in California, 34 and by Kreller et al on emissions monitoring in engine dynamometers. 38 However, no field tests have ever been reported for the MPES technology for natural gas emissions detection.…”