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Electrolyser and PGM

An electrolyser is a device that uses electricity to split water (H₂O) into hydrogen (H₂) and oxygen (O₂) through a process called electrolysis. Electrolysers play a key role in producing green hydrogen, which is increasingly seen as a crucial element in the transition to renewable energy. The electrolyser consists of different components such as an anode, cathode, electrolyte, and membrane, all working together to carry out the electrochemical reaction.

Types of Electrolysers:

1. Alkaline Electrolyser: One of the most established technologies, it uses a liquid electrolyte solution like potassium hydroxide (KOH).
2. Proton Exchange Membrane (PEM) Electrolyser: Uses a solid polymer membrane as the electrolyte, offering fast response times and high efficiency.
3. Solid Oxide Electrolyser (SOEC): Operates at high temperatures and can convert water and CO₂ into hydrogen and syngas.

Connection to Platinum Group Metals (PGMs):

PGMs, particularly platinum (Pt) and iridium (Ir), play a significant role in electrolysers, especially in PEM electrolysers, which are gaining traction due to their high efficiency and flexibility. Here’s how:

1. Catalysts:

   • Platinum is used as a catalyst on the cathode side of PEM electrolysers to speed up the hydrogen evolution reaction (HER), where protons are reduced to form hydrogen gas.
   • Iridium is commonly used on the anode side to catalyze the oxygen evolution reaction (OER), where water is split to produce oxygen.

2. Durability: PGMs are highly resistant to corrosion, which makes them ideal for the harsh electrochemical environment in the electrolyser, ensuring longer life and reliability of the device.

3. Cost and Supply:

   • One of the challenges in scaling up electrolyser technology, particularly PEM electrolysers, is the cost of PGMs, which are rare and expensive. Platinum and iridium are critical for the performance of the electrolysers but their scarcity makes cost a limiting factor.
   • Recycling and recovery of PGMs from catalytic converters and other industrial applications are becoming increasingly important to support the growing demand for electrolysers.

4. Research and Development:

   • Significant R&D efforts are focused on reducing the amount of PGM required for electrolysers or finding alternative materials. However, PGMs remain the most efficient catalysts for electrolysis processes due to their excellent conductivity and chemical stability.

Importance in Green Hydrogen Economy:

PGM-based electrolysers are key to producing green hydrogen, which is hydrogen generated from renewable electricity (such as wind or solar). This hydrogen can be used for various purposes, including:

• Energy storage: Storing excess renewable energy in the form of hydrogen.
• Fuel for transportation: Hydrogen fuel cells, which also use PGMs (mainly platinum), can power vehicles like buses, trucks, and even ships.
• Industrial use: Hydrogen is used in industries such as steel production and refining.

In summary, PGMs are essential for the performance and durability of PEM electrolysers, making them a cornerstone technology in the shift towards a green hydrogen economy. However, their high cost and limited availability drive the need for innovations in catalyst materials or PGM recycling strategies.

Recycling platinum group metals (PGMs) is crucial both environmentally and economically. These metals, used extensively in electrolysers and fuel cells, are rare and expensive to mine, making recycling a sustainable and cost-effective alternative. Environmentally, recycling reduces the need for new mining operations, which can have significant ecological impacts such as habitat destruction and water contamination. Economically, PGM recycling conserves precious resources, lowers production costs, and supports the circular economy by reusing critical materials.

At A. G. Metals, we can assist in the recovery and recycling of PGMs from various industrial applications, including electrolysers, ensuring these valuable metals are reused efficiently while minimizing environmental harm.