Porous Electrode Design Boosts Green Hydrogen Production by Limiting Bubbles

A multidisciplinary team from UNSW, in collaboration with TotalEnergies and EPFL, has developed a novel approach to increase the efficiency of green hydrogen production. The solution centers on optimizing the design of electrolyzers, devices that use electricity to split water into hydrogen and oxygen. When powered by renewable energy, this process yields "green hydrogen."

A major hurdle in industrial-scale electrolyzers has been the accumulation of hydrogen bubbles within porous electrodes. This buildup obstructs active sites and severely restricts mass transport, particularly at high current densities. "Green hydrogen production through water electrolysis is essential for decarbonizing hard-to-abate sectors such as steelmaking and heavy-duty transport," stated Prof. Peyman Mostaghimi, lead researcher from UNSW.

The research team employed X-ray imaging combined with simulations to gain unprecedented insight into the behavior of gas bubbles within the porous electrode structures over time, without needing to disassemble the electrolyzer. "We found that the shape and structure of the porous electrode are just as important as the electrochemistry," Prof. Mostaghimi explained. "If the structure is designed properly, you can stop bubbles from clogging the system and make it much more efficient."

Their findings revealed that a highly ordered and uniform pore structure within the electrodes resulted in minimal gas trapping. This indicates a direct link between pore structure and gas accumulation, offering manufacturers a clear path toward designing more efficient electrolyzer systems. This study also marked the first use of operando synchrotron imaging alongside advanced pore-scale numerical methods to visualize hydrogen bubble formation, growth, and accumulation during electrolysis.