Austrian study finds thin platinum coating can reduce metal use in hydrogen equipment by up to 88%

Researchers at the Vienna University of Technology in Austria have found that using thinner platinum coatings can effectively protect components used in hydrogen production. The discovery has the potential to reduce the precious metal required for these protective layers by approximately 88%. The study examined platinum-coated titanium bipolar plates used in proton exchange membrane (PEM) water electrolysis. Under the study conditions, coatings just 24 nanometers thick remained largely intact and maintained good electrical conductivity after electrochemical stress. The findings point to a possible pathway for reducing equipment costs. However, the researchers caution that the optimal thickness depends on multiple factors, including how the coating is manufactured and the uniformity of its surface coverage. Why hydrogen equipment needs platinum. Metal electrolysis uses electricity to split water into hydrogen and oxygen. At one electrode, the process produces oxygen, positively charged hydrogen ions (protons), and electrons. The protons pass through a membrane to reach the second electrode, where they combine with electrons to form hydrogen. Keeping equipment running in this environment is more difficult than the basic reaction suggests. "The electrolysis process creates a chemical environment that is harmful to many metal components. Metals can dissolve, while oxide layers can also form, impeding current flow," explains Helmut Riedl-Tragenreif of the Institute of Materials Science and Technology at the Vienna University of Technology.

Platinum demand for hydrogen equipment

"If the system is to operate long-term, the individual components must be carefully matched. The bipolar plate plays a particularly important role here, accounting for up to 30% of total system costs." These plates not only mechanically support the equipment but also conduct current and help transport water and gases. Titanium has good corrosion resistance, but an oxide layer forms on its surface that impedes current flow. A thin platinum coating solves this problem, protecting the titanium while effectively conducting current. Thin coatings survive testing. The Vienna University of Technology team systematically investigated how thick the protective layer needs to be.

Thin platinum coating test results

Testing showed that a 24-nanometer-thick coating was sufficient under the conditions tested, while an 8-nanometer coating showed clear problems. Compared to the 200-nanometer coatings currently used in industry, the successful thin coating represents a potential reduction in platinum consumption of approximately 88%. The researchers also examined how these coatings withstand electrochemical stress, rather than merely assessing their initial performance. "We used high-resolution methods to analyze the coatings before and after electrochemical stress. A particularly important question is whether microscopic defects appear in the coating."

Riedl-Tragenreif said. Small defects can accelerate damage. Defects in the platinum layer can expose the underlying titanium to attack. The titanium oxidizes, and small oxygen bubbles can form at the interface, creating mechanical stress that further damages the coating. As larger areas delaminate, more titanium is exposed, and the damage accelerates. The 8-nanometer coating showed clear signs of this process. After electrochemical stress, the researchers observed larger defects and found a significant increase in the amount of titanium and platinum ions entering the electrolyte. The 24-nanometer coating, by contrast, remained largely intact under the conditions studied, maintained good conductivity, and kept metal ion release at very low levels.

Impact of thin platinum coatings on hydrogen production

In hydrogen production, the amount of platinum used has a significant impact on costs. The study shows that thin platinum coatings can effectively reduce precious metal demand, which not only reduces production costs but also improves equipment durability. The design and material selection of bipolar plates are crucial to overall system performance, especially when facing the challenge of chemical corrosion. The findings of this study could promote the commercialization of hydrogen technology and drive more sustainable energy solutions.