High-Performance Supported Iridium Oxohydroxide Water Oxidation Electrocatalysts.
The synthesis of a highly active and yet stable electrocatalyst for the anodic oxygen evolution reaction (OER) remains a major challenge for acidic water splitting on an industrial scale. To address this challenge, we obtained an outstanding high-performance OER catalyst by loading Ir on conductive antimony-doped tin oxide (ATO)-nanoparticles by a microwave (MW)-assisted hydrothermal route. The obtained Ir phase was identified by using XRD as amorphous (XRD-amorphous), highly hydrated IrIII/IVoxohydroxide. To identify chemical and structural features responsible for the high activity and exceptional stability under acidic OER conditions with loadings as low as 20 μgIrcm-2, we used stepwise thermal treatment to gradually alter the XRD-amorphous Ir phase by dehydroxylation and crystallization of IrO2. This resulted in dramatic depletion of OER performance, indicating that the outstanding electrocatalytic properties of the MW-produced IrIII/IVoxohydroxide are prominently linked to the nature of the produced Ir phase. This finding is in contrast with the often reported stable but poor OER performance of crystalline IrO2-based compounds produced through more classical calcination routes. Our investigation demonstrates the immense potential of Ir oxohydroxide-based OER electrocatalysts for stable high-current water electrolysis under acidic conditions.
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.|Department of Heterogenous Reactions, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim-an-der-Ruhr, Germany.
Cyriac
0000-0002-1575-5057
C
Massué
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
Verena
V
Pfeifer
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
Xing
X
Huang
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
Johannes
J
Noack
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
Andrey
A
Tarasov
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.
Sébastien
0000-0002-9022-0757
S
Cap
Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195, Berlin, Germany.|Department of Heterogenous Reactions, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim-an-der-Ruhr, Germany.
Robert
R
Schlögl
D002384:Catalysis; D003460:Crystallization; D004563:Electrochemistry / Q000379:methods*; D004572:Electrolysis; D007495:Iridium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen; D014867:Water / Q000737:chemistry*
D014867:Water; C044458:iridium oxide; D007495:Iridium; D010100:Oxygen
electrocatalysis; energy storage; iridium; oxygen evolution reaction; water splitting