Porous Iridium Oxide Inverse Opal Catalysts Enable Efficient PEM Water Electrolysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41492805.
- Also identified by DOI 10.1002/adma.202514659 and PMC identifier 12921350.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Green hydrogen produced by proton exchange membrane water electrolysis (PEM-WE), has gained significant attention as a future energy carrier and as a feedstock for the chemical industry. Reducing the use of scarce iridium in PEM-WE anodes is a critical requirement. In this work, porous iridium-based inverse opal structures (IrO<sub>x</sub>-IO) of varying pore sizes are introduced as novel unsupported bulk anode catalysts and their superior performance compared to commercial alternatives is demonstrated. The influence of porosity and surface area on the electrochemical performance is systematically investigated and categorized using voltage breakdown analysis and equivalent circuit modeling. Efficient IrO<sub>x</sub>-IO operation requires balancing surface area and pore size, enabling high performance up to 13 A cm<sup>-</sup> <sup>2</sup> with iridium utilizations below 0.1 g<sub>Ir</sub>/kW at 70% efficiency. The findings advance our understanding of unsupported bulk catalysts and, more importantly, expand the range of viable anode materials by clarifying how catalyst morphology influences electrode reactivity.