Ionomer-free and recyclable porous-transport electrode for high-performing proton-exchange-membrane water electrolysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37524721.
- Also identified by DOI 10.1038/s41467-023-40375-x and PMC identifier 10390546.
- 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
Clean hydrogen production requires large-scale deployment of water-electrolysis technologies, particularly proton-exchange-membrane water electrolyzers (PEMWEs). However, as iridium-based electrocatalysts remain the only practical option for PEMWEs, their low abundance will become a bottleneck for a sustainable hydrogen economy. Herein, we propose high-performing and durable ionomer-free porous transport electrodes (PTEs) with facile recycling features enabling Ir thrifting and reclamation. The ionomer-free porous transport electrodes offer a practical pathway to investigate the role of ionomer in the catalyst layer and, from microelectrode measurements, point to an ionomer poisoning effect for the oxygen evolution reaction. The ionomer-free porous transport electrodes demonstrate a voltage reduction of > 600 mV compared to conventional ionomer-coated porous transport electrodes at 1.8 A cm<sup>-2</sup> and <0.1 mg<sub>Ir</sub> cm<sup>-2</sup>, and a voltage degradation of 29 mV at average rate of 0.58 mV per 1000-cycles after 50k cycles of accelerated-stress tests at 4 A cm<sup>-2</sup>. Moreover, the ionomer-free feature enables facile recycling of multiple components of PEMWEs, which is critical to a circular clean hydrogen economy.