Study in Materials Today reports a new stainless steel (SS-H2) using a dual-passivation mechanism that resists corrosion up to 1700 mV, enabling cheaper seawater electrolysis.
Key Takeaways
SS-H2 forms a secondary manganese-based passive layer at ~720 mV on top of the standard Cr2O3 film, pushing corrosion resistance to 1700 mV vs. ~1000 mV for conventional stainless steel.
Conventional and super stainless steels like 254SMO fail in PEM electrolyzer conditions because Cr2O3 oxidizes into soluble Cr(VI) at high potentials, well below water oxidation voltage.
In seawater electrolyzers, SS-H2 performs comparably to titanium-gold/platinum structural components at roughly 40x lower material cost.
For a 10 MW PEM system where structural components are ~53% of total cost, the cost reduction is substantial at scale.
Industrialization is underway: tons of SS-H2 wire produced with a mainland China factory; patents granted in multiple countries.
