Size-Controlled Synthesis of IrO2 nanoparticles at High Temperatures for the Oxygen Evolution Reaction

• DOI: 10.1149/ma2023-01362023mtgabs
• Publication Date: 2023-09-19T23:01:53Z
• Authors: Marko Malinovic; Paul Paciok; Ezra Shanli Koh; Moritz Geuß; Jisik Choi; Philipp Pfeifer; Jan Philipp Hofmann; Daniel Göhl; Marc Heggen; Serhiy Cherevko; Marc Ledendecker
• Keywords: Oxygen evolution; Electrolysis of water

Polymer electrolyte membrane (PEM) electrolysis is considered to play a vital role in the sustainable energy transition. The efficient generation of hydrogen largely influenced by slow rate anodic oxygen evolution reaction (OER). Iridium oxide represents one most promising catalysts for electrochemical oxidation water an acidic environment. Under harsh operating conditions at anode, iridium found be among dissolution-resistant while offering acceptable OER activity. However, iridium’s limited availability dictates high costs centralizing research direction reducing noble metal content maintaining favorable properties. [1] Designing nanostructured catalyst with increased surface-to-volume ratio improves application-oriented mass-specific [2] Hydrous known superior activity, but successful application, drastic dissolution must addressed stabilization. This can achieved heat treatment temperatures ≥400ºC formation crystalline order. managing avoid agglomeration nanoparticles not trivial, thus, temperature studies on stability and activity similar particle sizes are missing. [3] . Here, we demonstrate how below 10 nm obtained preparation up 800 °C unprecedented control over size morphology. A detailed understanding structural during heating was in-situ scanning transmission electron microscopy ( STEM) locally resolved nanoparticles, spatial resolution, chemical specificity. Additionally, changes surface properties different were tracked ex-situ X-ray photoelectron spectroscopy (XPS), crystal structure investigated diffraction analysis (XRD), morphology characterized high-angle annular dark-field (HAADF-STEM). activities synthesized measured half-cell measurements forced convection. carefully studied operando flow cell that coupled online inductively plasma mass spectrometry. [4] calcined lowest resulted outstanding outperforming reference factor 40. By gradual increase calcination °C, observe improvement durability catalysts, being comparable catalyst, yet still notable catalytic first report synthesize preserved exceeding allows determination similarly sized nanostructures. [5] Literature: M. Bernt et al. Chemie Ingenieur Technik 2020, 92, 31-39. T. Reier, ACS Catalysis 2012, 2, 1765-1772. Y. Lee Journal Physical Chemistry Letters 3, 399-404. S. Geiger Nature 2018, 1, 508-515. M.Malinovic Advanced Energy Materials 2022, Manuscript submitted publication.