Leak Detection and H₂ Sensor Development

Technical Report · Tue Jul 10 00:00:00 EDT 2012

DOI:https://doi.org/10.2172/1045977· OSTI ID:1045977

Brosha, Eric L. ^[1]

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1. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Low-cost, durable, and reliable Hydrogen safety sensor for vehicle, stationary, and infrastructure applications. A new zirconia, electrochemical-based sensor technology is being transitioned out of the laboratory and into an advanced testing phase for vehicular and stationary H₂ safety applications. Mixed potential sensors are a class of electrochemical devices that develop an open-circuit electromotive force due to the difference in the kinetics of the redox reactions of various gaseous species at each electrode/electrolyte/gas interface, referred to as the triple phase boundary (TPB). Therefore, these sensors have been considered for the sensing of various reducible or oxidizable gas species in the presence of oxygen. Based on this principle, a unique sensor design was developed by LANL and LLNL. The uniqueness of this sensor derives from minimizing heterogeneous catalysis (detrimental to sensor response) by avoiding gas diffusion through a catalytically active material and minimizing diffusion path to the TPB. Unlike the conventional design of these devices that use a dense solid electrolyte and porous thin film electrodes (similar to the current state-of-the-art zirconia-based sensors and fuel cells), the design of this sensor uses dense electrodes and porous electrolytes. Such a sensor design facilitates a stable and reproducible device response, since dense electrode morphologies are easy to reproduce and are significantly more stable than the conventional porous morphologies. Moreover, these sensors develop higher mixed potentials since the gas diffusion is through the less catalytically active electrolyte than the electrode. Lastly, the choice of electrodes is primarily based on their O2 reduction kinetics and catalytic properties vis-a-vis the target gas of interest.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1045977
• Report Number(s): LA-UR--12-22809
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
36 MATERIALS SCIENCE
42 ENGINEERING
DESIGN
DETECTION
DIFFUSION
ELECTRODES
ELECTROLYTES
ELECTROMOTIVE FORCE
Energy Sciences
Engineering(42)
HETEROGENEOUS CATALYSIS
HYDROGEN
Hydrogen(08)
KINETICS
Materials Science(36)
OXYGEN
REDOX REACTIONS
SAFETY
SENSORS
SOLID ELECTROLYTES
TARGETS
TESTING
THIN FILMS