Electrolysis is near parity as an energy storage process when compared to the cost of competing technologies, including batteries, pumped hydro, and compressed air.[1] When coupled with renewable energy sources, such as wind and solar, electrochemical water splitting can also produce hydrogen using a nearly carbon free pathway.[1]  Some overview content will be presented to provide justification for decreased capital costs in electrolyzers as well as focus on aspects of intermittent operation.  An operational mode not used typically today in electrolysis, but one that will become of higher interest in the future with increasing renewable energy penetration and growing hydrogen markets.

Iridium nanoparticles are commonly used as electrocatalysts in acidic electrolyzers due to moderate stability and activity in the oxygen evolution reaction (OER). Baseline materials and protocols are still being developed to benchmark the current status of OER catalysts.  The presentation will discuss results along these lines, as well as discuss mercury underpotential deposition as a method for determining surface area for iridium and/or iridium oxide.

Progress made at NREL on Ir based nanowires for OER that leverage off of previous experiences in the production of Pt based nanowires for oxygen reduction reaction [2] will also be presented.

References

[1] K. Harrison, M. Peters, in: U.S. Department of Energy (Ed.), http://www.hydrogen.energy.gov/pdfs/review13/pd031_harrison_2013_o.pdf, 2013.

[2]  S.M. Alia, Y. Yan, B.S. Pivovar, “Galvanic Displacement as a Route to Highly Active and Durable, Extended Surface Electrocatalysts” Catalysis Science and Technology, 2014, 4 (10), 3589 - 3600.