Toward Low Loading and High Utilization Ratio of Iridium Catalyst for PEM Water Electrolyzers Using Smoltek Carbon Nanofibers

Smol­tek addresses the hydro­gen industry’s main chal­lenges for enabling cost-effi­cient pro­duc­tion of fossil-free hydro­gen by dra­mat­ic­ally redu­cing the cost of PEM water electrolyzers. 

• By focus­ing on:
• Anode side cata­lyst is expensive.
• Good elec­tric­al con­duct­iv­ity is important.

• We can:
• Increase anode sur­face area by Smol­tek CNFs.
• Lower Ir load­ing amount to ≤0.2 mg Ir/​cm2.

• We do this by grow CNFs on anode PTLs:
• Cre­at­ing a Cata­lyst coated PTL substrate
• Where the CNFs increase sur­face area (CNF length can be con­trolled from 1 to 30 µm)
• Cor­ro­sion pro­tec­tion: CNFs covered with a 50 nm Pt lay­er and an elec­trode­pos­ited Ir layer

• This res­ults in:
• Con­trolled Ir load­ing by our own depos­ition process
• Decrease Ir cata­lyst load­ing to as low as 0.1 mgIr/​cm2
• Per­form­ance is bet­ter than com­mer­cial Ir cata­lyst ink