For large-scale application of hydrogen generation via the so-called proton exchange membrane (PEM) water electrolysis it is particularly essential to reduce the currently high amounts of iridium in the oxygen evolution electrode. In a new publication at the Chair of Technical Electrochemistry, an oxygen evolution reaction catalyst with significantly reduced iridium loading was compared to a commercially available benchmark catalyst. Due to a reduced iridium packing density as well as a higher activity – even at a 9-fold lower iridium loading – the new catalyst achieved a higher performance. In combination with different porous transport layers, however, limitations due to the lower electrical conductivity of the new catalyst material occurred. To avoid interfacial contact resistances by increasing the catalyst conductivity, a heat treatment procedure was successfully applied.
The complete results of the study published in the Journal of the Electrochemical Society are openly accessible here.