Hydrogen as an energy carrier is an important part of the solution to the energy challenge for the future. One method of producing hydrogen is through electrolysis of water. In an electrolysis cell, two electrodes and an electrolyte are needed. For efficient operation the electrodes are coated with catalysts. On the oxygen producing side, the anode, the catalyst is based on the scares and expensive element iridium. This contributes to a high-cost level for PEM electrolysers and places limitations on the production volume of this technology.
Limited conductivity of the catalytic layer, degradation of the catalyst and deterioration of the interfaces over time reduces the performance. A relatively high concentration of iridium must be used to have an acceptable lifetime. In HOPE we address the issues in several approaches with the aim of reducing or replacing the iridium catalyst. We will develop and test ruthenium pyrochlore catalysts and evaluate these for their oxygen evolution performance and suitability for the PEM application. In addition, HOPE addresses the improvement of the boundary layer between the catalyst-coated membrane and the adjacent transport layer. Traditionally, the titanium-based porous transport layer (PTL) used on the anode is not optimized for PEM water electrolysers. They often have large pores and contact poorly to the catalyst layer on the membrane. Poor contact increases the required electrical conductivity of the catalytic layer, resulting in the need for high Ir concentrations at the anode. In HOPE we will work on the development of new PTL’s with microporous structure to optimize this architecture. The new components and new architectures will be tested electrochemically at the Norwegian Fuel Cell and Hydrogen Centre (FCH) as well as addressed through electrochemical modelling.
At HOPE we work closely with Professor Frode Seland and Professor Svein Sunde from the Department of Materials Technology at NTNU and their PhD student Megan Heath.
