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PEM Electrolyzers: Powering the Future of Green Hydrogen
Oct, 2025
Green hydrogen is gaining serious momentum as a clean energy solution—and at the heart of this revolution are Proton Exchange Membrane (PEM) electrolyzers. These systems are not just efficient (boasting conversion rates of 80–90%) but also produce ultra-pure hydrogen (>99.9%) with a fast dynamic response, making them ideal for distributed and small-scale applications.
Unlike traditional alkaline electrolyzers, which rely on liquid potassium hydroxide, PEM systems use a solid polymer membrane and require high-purity water to function optimally. They typically operate at moderate temperatures and pressure —around 30 bar —which simplifies integration into various setups.
Why PEM Electrolyzers Matter
As the global energy sector pushes to reduce the cost of green hydrogen, PEM technology is front and center. Its scalability and compatibility with renewable energy sources make it a strong candidate for widespread adoption. But there’s a catch: the current cost of hydrogen produced via PEM electrolyzers hovers around $6.70/kg. That’s largely due to the high capital costs and the use of expensive materials, including platinum group metals.
Driving Down Costs: The Research Frontier
To make PEM electrolyzers more economically viable, researchers are exploring several promising avenues:
- Reducing iridium loading in the oxygen evolution electrode
- Replacing Nafion membranes with lower-cost alternatives
- Developing new materials for the Porous Transport Layer (PTL)
- Improving manufacturing techniques for better scalability
But it’s not just about the core electrolyzer. The Balance of Plant (BOP)—everything else that supports the production—also needs optimization.
Filtration: The Unsung Hero of System Efficiency
Filtration of the feed water plays a critical role in maintaining system performance and longevity. Impurities in water can wreak havoc:
- Metal ions and organics can degrade the membrane, reducing conductivity and lifespan.
- Catalyst poisoning (especially platinum and iridium) lowers efficiency and durability.
- Scaling and clogging from minerals and particulates lead to frequent maintenance.
To combat these issues, Reverse Osmosis (RO) and Electrodeionization (EDI) systems are used to generate high purity water. These units also need protection and Pall Corporation offers a variety of particulate filters for this purpose.
Post-Electrolysis Filtration: Managing Moisture and Oil
Once hydrogen is produced, it’s saturated with water and contains free water droplets. These droplets must be removed to reduce loading of the de-oxo and dryer units. After compression using oil lubricated compressors, the lube oil must be removed before the hydrogen is used. Pall’s SepraSol® and SepraSol® Plus liquid/gas coalescers are designed to:
- Remove free water before and after de-oxo units, optimizing catalyst beds and dryers.
- Eliminate oil contamination after hydrogen compression, ensuring purity and protecting downstream equipment.
Looking Ahead
PEM electrolyzers are a cornerstone technology in the clean hydrogen landscape. As innovations in membrane materials, system integration, and filtration continue to evolve, we move closer to making green hydrogen cost-competitive and widely accessible.
Pall Corporation remains committed to supporting this transition, offering filtration solutions that meet both current and emerging challenges in hydrogen production.
To learn more about how we are advancing filtration technologies for green hydrogen production, visit our Hydrogen Filtration Solutions page