Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

High surface area (∼300 m2/g) nanostructured powders of nominal composition (Nb1−xIrx)O2 and (Nb1−xIrx)O2:10F have been synthesized and tested as oxygen evolution electro-catalysts for PEM based water electrolysis using a simple two-step chemical synthesis procedure. Superior electrochemical activity was demonstrated by fluorine doped compositions of (Nb1−xIrx)O2 with an optimal composition (Nb0.75Ir0.25)O2:10F (x = 0.25) demonstrating on-par performance with commercial hydrated IrO2 and nanostructured in-house chemically synthesized IrO2. Using first principles calculations, the electronic structure modification resulting in ∼75 at.% reduction (experimentally observed) in noble metal content without loss in catalytic performance and stability has been established.160