Description: Future NASA missions require high efficiency, lightweight, long life, and maintenance-free water electrolyzer technologies to generate oxygen and/or hydrogen for energy storage, propulsion, life-support systems, cabin-oxygen replenishment, and zero-g science activities. International Space Station, future Lunar and Martian Outposts, and future exploration vehicles require high efficiency electrolyzers to improve their operational capabilities for long and complex missions. The oxygen evolution reaction is the limiting step due to non-optimal electrocatalyst structure. State-of-the-art electrocatalysts do not meet MEA efficiency and lifetime requirements for NASA applications. Advanced electrocatalysts are needed. In the Phase I, Lynntech manufactured a binary nanoparticle surface decorated mixed oxide electrocatalyst with the optimal microstructure and demonstrated an MEA efficiency of >90% (i.e., an electrolysis potential of 1.358 V/cell) at 200 mA/cm2. In the Phase II program, Lynntech will investigate different catalyst morphologies to improve the lifetime. In addition, ternary transition metal oxides will be incorporated into the mixed oxide to further increase the efficiency and lifetime. The applicability of this advanced catalyst to different membranes will be investigated. Nanocomposite membranes with low hydrogen gas cross-over will be manufactured and tested. A short electrolyzer stack will be assembled with the optimized components, tested and delivered to NASA.

Benefits: Potential non-NASA applications for this OER catalyst are energy storage for use with intermittent renewable sources such as solar, tidal, and wind power, hydrogen and oxygen generation for residential and stationary applications, efficient generation of hydrogen fuel using off-peak electricity, O2 generation for medical applications such as hospitals, deployed field hospitals and portable O2 concentrators. In addition, mixed metal oxide catalyst can have immediate use for gas sensing applications to detect numerous toxic, poisonous and otherwise harmful gases.

Some of the potential NASA applications for the advanced OER catalyst are listed below. The advanced OER catalyst developed in this project can replace the current state-of-the-art anode catalysts in the following applications: 1. Electrolyzers in regenerative fuel cell systems for storing energy in the form of hydrogen and oxygen via water electrolysis (lunar and planetary fixed base energy storage, recharge of lunar rovers, portable power fuel cells, etc.). 2. PEM electrolyzers systems for oxygen generation (for environmental control, crew life support, replenishing the oxygen for cabin, pre-breath oxygen delivery unit prior to space walking, propulsion for in-space maneuvering, in-space science activities, etc.). 3. Electrochemical oxygen concentrators (oxygen concentration from cabin air for medical emergencies, portable back-up oxygen storage, etc.).