Ultrathin Platinum Coatings Could Cut Electrolyzer Hardware Costs, Study Finds

Protective platinum coatings used on titanium bipolar plates in proton exchange membrane (PEM) water electrolyzers can be thinned to 24 nanometers without losing structural integrity or conductivity under operational strain, according to research from TU Wien published in ACS Applied Materials & Interfaces and reported by TechXplore (https://techxplore.com/news/2026-10-platinum-cheaper-hydrogen-ultrathin-electrolyzer.html).

PEM electrolysis splits water into oxygen, protons, and electrons, with protons crossing a membrane to form hydrogen gas. The process creates a corrosive chemical environment that can dissolve metallic parts and form resistive oxide layers. To withstand these conditions, manufacturers use titanium bipolar plates, which provide structural stability, conduct current, and transport fluids. These plates account for up to 30 percent of total electrolyzer system costs.

Titanium resists corrosion in these systems but naturally develops an oxide layer that impedes electrical conductivity. Manufacturers coat the plates in platinum to maintain conductivity and protect the substrate, routinely applying layers 200 nanometers thick or more.

A research team led by Helmut Riedl-Tragenreif at TU Wien's Institute of Materials Science and Technology tested how thin these coatings could be made before failing. Testing showed that an 8-nanometer coating failed under electrochemical stress, forming microscopic defects where exposed titanium oxidized, created interface gas bubbles, and caused the platinum film to detach while leaching metal ions into the electrolyte.

By contrast, a 24-nanometer platinum layer remained largely intact under the studied test conditions, retained high electrical conductivity, and kept metal ion release to low levels. Compared to standard 200-nanometer industrial coatings, the 24-nanometer layer represents an approximate 88 percent reduction in platinum used for plate protection.

Riedl-Tragenreif noted that while the precise optimal thickness in commercial settings will depend on deposition methods and coating uniformity, materials science testing confirms that standard several-hundred-nanometer layers are not strictly necessary to prevent component degradation.