Iridium-Tantalum Mixed Metal Oxides for the Acidic Oxygen EvolutionReaction

Green hydrogen will play a crucial role in decarbonizing industry branches that today rely heavily on fossil fuels such as chemicals, steel, or the transportation sector and enables new ways for energy storage. Polymer electrolyte membrane water electrolysis (PEMWE) offers a high current density and can run at dynamic load ranges, making it ideal for use with renewable energy sources. Even though hydrogen is the main product, the efficiency of the PEMWE is largely influenced by the sluggish oxygen evolution reaction (OER) at the anode, which forms the bottleneck of this reaction.Looking at the so-called Pourbaix-Diagrams, which give information on the thermodynamic stability, only a handful of metals can withstand the harsh conditions of the oxygen evolution reaction, among those Ir, Nb, Ta, and Ti, which the EU classifies as critical raw materials. While iridium oxide-based catalysts are considered state-of-the-art in this field due to their high stability and good activity