The project deals with preparation, thorough characterization and testing of novel nanostructured materials and catalysts for use in proton exchange membrane water electrolyzers. Catalysts will be designed with emphasis on reducing the noble metal loading without significant performance drop. We will approach the task from two different directions: i) We will study new high-surface catalyst supports in order to enlarge the active area of catalyst. ii ) We will focus on creating mixed, multi-elemental catalysts in form of alloys and oxides, where noble metal will be mostly replaced by cheaper alternative. Due to the project multidisciplinary character the research team will be composed of 5 young experts covering all experimental techniques involved in the project. As a result, the knowledge-based model approach will have a direct impact on catalyst development in a real system and eventually will lead to water electrolyzer prototype. This approach makes the project unique, not only from the point of view of scientific advances, but also of technological and economic impacts.