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Updated: Jul 25, 2025

Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device
Published on: July 20, 2021
IrO·nH2O with lattice water-assisted oxygen exchange for high-performance proton exchange membrane water
Jun Xu1, Huanyu Jin1,2, Teng Lu3
1School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia.
Abstract:
The trade-off between activity and stability of oxygen evolution reaction (OER) catalysts in proton exchange membrane water electrolyzer (PEMWE) is challenging. Crystalline IrO2 displays good stability but exhibits poor activity; amorphous IrO exhibits outstanding activity while sacrificing stability. Here, we combine the advantages of these two materials via a lattice water-incorporated iridium oxide (IrO·nH2O) that has short-range ordered structure of hollandite-like framework. We confirm that IrO·nH2O exhibits boosted activity and ultrahigh stability of >5700 hours (~8 months) with a record-high stability number of 1.9 × 107 noxygen nIr-1. We evidence that lattice water is active oxygen species in sustainable and rapid oxygen exchange. The lattice water-assisted modified OER mechanism contributes to improved activity and concurrent stability with no apparent structural degradation, which is different to the conventional adsorbate evolution mechanism and lattice oxygen mechanism. We demonstrate that a high-performance PEMWE with IrO·nH2O as anode electrocatalyst delivers a cell voltage of 1.77 V at 1 A cm-2 for 600 hours (60°C).
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