Researchers at the University of Hong Kong (HKU) have developed a new type of stainless steel, SS-H2, designed for cost-effective hydrogen production from seawater. Led by Professor Ming-Hsin Huang, this innovative material exhibits exceptional corrosion resistance in challenging electrolysis environments, where traditional stainless steels fail due to their inability to handle high voltages associated with seawater electrolysis.
The findings, published in Materials Today, highlight SS-H2’s potential to drastically reduce the costs of electrolysis systems. Current titanium-based materials are expensive and can comprise over half the total system cost. By integrating SS-H2, costs could be reduced significantly.
The steel functions due to a novel “sequential dual passivation” strategy. This involves creating a protective chromium-based layer followed by a manganese-based layer, which protects against chloride-induced corrosion, enhancing performance at high potentials. This groundbreaking mechanism diverges from traditional beliefs that manganese weakens stainless steel.
The research has spanned nearly six years and has led to patents and the initial production of SS-H2 materials. Although challenges remain in transforming this research into practical applications, the steel presents a promising solution for sustainable hydrogen energy, making it cheaper and more scalable. The development is significant as the field continues to confront issues of corrosion and material durability in seawater electrolysis, positioning SS-H2 as a key player in the transition to renewable energy sources.
