Balancing activity, stability and conductivity of nanoporous core-shell iridium/iridium oxide oxygen evolution catalysts

• DOI: 10.1038/s41467-017-01734-7
• Publication Date: 2017-11-07T12:45:44Z
• Authors: Yong-Tae Kim; Pietro Papa Lopes; Shin-Ae Park; A-Yeong Lee; Jinkyu Lim; Hyunjoo Lee; Seoin Back; Yousung Jung; Nemanja Danilovic; Vojislav Stamenkovic; Jonah Erlebacher; Joshua Snyder; Nenad M. Markovic
• Keywords: Nanoporous; Oxygen evolution

The selection of oxide materials for catalyzing the oxygen evolution reaction in acid-based electrolyzers must be guided by proper balance between activity, stability and conductivity-a challenging mission great importance delivering affordable environmentally friendly hydrogen. Here we report that highly conductive nanoporous architecture an iridium shell on a metallic core, formed through fast dealloying osmium from Ir25Os75 alloy, exhibits exceptional activity as quantified activity-stability factor. On basis this metric, Ir/IrO2 morphology dealloyed shows factor ~30 improvement relative to conventional iridium-based materials, ~8 times over nanoparticles due optimized conductivity, respectively. We propose is key "metric" determining technological relevance oxide-based anodic water electrolyzer catalysts.