Electrolyzers
Polymer electrolyte membrane (PEM) electrolysis is used on-board submarines to generate breathing oxygen for the crew. Expensive noble metals are used as electrocatalysts, and Membrane Electrode Assemblies (MEAs) that contain these precious metals contribute to approximately 25% of the cost of the electrolysis cell. Greatly reducing or eliminating the amount of noble metal electrocatalysts would significantly reduce the cost of the electrolysis cell stack; the Navy estimates that the cost savings would be ~$200,000 per electrolysis stack. Non-noble metal electrocatalysts are being developed, but so far no alternative has matched the performance of current Pt electrocatalysts.
TDA is developing Pt on carbon electrocatalysts that can run the hydrogen evolution reaction (HER) with platinum metal loadings of 0.1 mg/cm2 or less.
Provides performance (both initially and over time) that is comparable to today’s membrane electrode assemblies (MEAs) that use 1.0 mg/cm2 of Pt.
Provide a carbon support that allows the Pt to be dispersed more efficiently.
Provides appropriately sized pathways (pores that let the water reach the active Pt site, while giving the gases a way out).
Provides high electrical conductivity so that the power needed to drive the electrolysis reaction is delivered efficiently to the Pt catalyst particles.
