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