We report here on potential candidates based on the oxides SnO 2 , Nb 2 O 5 , Ta 2 O 5 , and WO 3 as alternative support materials for precious metal catalysts with high stability under highly acidic conditions and elevated temperatures as well as sufficient electric conductivity (EC) for application in PEMFCs. To increase the low conductivity of these wide bandgap binary oxides we investigated the mutual doping of these elements and report here on the doping of SnO 2 with W, Nb and Ta in the doping range of 0-15 mol-% metal component. Powder samples were prepared by an optimized sol-gel method based on

The cover picture shows a hypothetical clustering of three Sn2+ ions (Sn''Sn) with stereochemically active lone pairs around an O2– vacancy (VO∙∙) in the tetragonal rutile‐type structure of SnO2 with octahedral coordination of the tin ions. Each O2– ion is trigonal planar coordinated by three Sn2+/4+ ions as well as 11 O2– in the tetragonal close packing of the rutile structure‐type. Internal redox reactions between Ta5+/Ta4+ and Sn4+/Sn2+ and possibilities to reduce the electrostatic repulsion between cations on introduction of anion vacancies into the crystal structure are also indicated. More details can be found in the Article by Klaus Stöwe, and Maximilian Weber on page 1470 ff.