Korean team develops platinum-free hydrogen electrolysis system

A research team from KAIST, led by Professor Hee-Tak Kim in collaboration with Dr. Gisu Doo from the Korea Institute of Energy Research, has developed a platinum-free proton exchange membrane water electrolysis (PEMWE) system that maintains high performance while significantly reducing costs. PEMWE is a promising technology for producing high-purity hydrogen using water and electricity, but its reliance on expensive metals like platinum and iridium has limited widespread adoption. The team identified that poor electron transport in PEMWE cells stems from a “pinch-off” effect at the interface where the iridium oxide (IrOx) catalyst, ionomer, and titanium substrate meet, with the ionomer acting as an electrical insulator and creating a conductivity barrier. To address this, the researchers focused on increasing the size of the IrOx catalyst particles, discovering that particles larger than 20 nanometers reduced pinch-off zones and improved electron flow without the need for platinum. Additionally, they optimized the catalyst layer structure to minimize