Role of components in Hydrogen Electrolyzer

A: In a PEM (Proton Exchange Membrane) electrolyzer, the membrane acts as a solid polymer electrolyte that conducts protons from the anode to the cathode while acting as a barrier to prevent the mixing of hydrogen and oxygen gases. This selective ion conduction is essential for the cell's operation and safety. The membrane's chemical stability and proton conductivity directly impact the electrolyzer's efficiency and longevity. Nafion is a commonly used membrane material. More technical details can be found here: https://www.sciencedirect.com/topics/chemical-engineering/proton-exchange-membrane

A: Electrodes in hydrogen electrolyzers are usually made from materials that offer high catalytic activity, electrical conductivity, and corrosion resistance. For the anode, materials like Iridium oxide or Ruthenium oxide are used because they facilitate the oxygen evolution reaction efficiently and resist oxidation. The cathode often uses platinum or similar noble metals, which catalyze hydrogen evolution effectively. Research is ongoing to find non-noble metal catalysts to reduce costs. This review paper provides insights: https://pubs.rsc.org/en/content/articlelanding/2019/ta/c8ta10100b

A: The electrolyte enables ion transport between the electrodes, which is vital for completing the electric circuit and sustaining the electrolysis reaction. Its properties, such as ionic conductivity, chemical stability, and compatibility with electrode materials, directly influence cell performance. Alkaline electrolyzers typically use aqueous potassium hydroxide solutions, while PEM electrolyzers use solid polymer membranes. Each type has its advantages and challenges regarding efficiency, durability, and operating conditions. Comprehensive comparisons are available in this overview: https://www.energy.gov/eere/fuelcells/hydrogen-electrolysis