APPLICATIONS OF TECHNOLOGY:
- PEM water electrolyzers
- Low catalyst loading
- One-step processing
- Easily recyclable
- Proton exchange membrane (PEM) electrolysis is a process by which water is electrochemically split into hydrogen and oxygen gas with a solid polymer electrolyte as the interface between the anode and cathode. PEM electrolyzers in particular show promise for their high current density, efficiency, and product gas purity. These electrolyzers are, however, faced with the problem of high material costs as a barrier to scale up because of the reliance on iridium (Ir) as a catalyst. The large amount of Ir needed for industrial scale hydrogen production means that PEM water electrolyzers cannot realistically be used at scale without further technological development.
Berkeley Lab researchers have developed a new method of fabricating porous transport electrodes (PTE) for PEM water electrolyzers. By depositing the IrOx catalyst directly onto the porous transport layer rather than the polymer membrane, scientists were able to decrease iridium loading without suffering a performance drop. Additionally, this process deposits the catalyst without an ionic conductor and binder so the catalyst can be directly recycled without any separation needed which increases the catalyst recovery. After running the device for 50,000 cycles and recycling the catalyst, only a small of Ir was lost.
This electrolyzer also demonstrates a very long lifetime. After 50,000 cycles the device only suffered a small performance drop, a minimal decrease relative to the testing parameters up to 4A/cm2. After 50,000 cycles the catalyst was recycled to assemble a new electrolyzer, which nearly matched the performance of the pristine electrolyzer. This method of fabricating the PTE thus provides for lower cost devices by reducing the Ir loading and increasing the Ir recovery rate in recycling.
DEVELOPMENT STAGE: Validated in laboratory setting
- Xiong Peng
- Keonhag Lee
- Adam Weber
- Nemanja Danilovic
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.