A proton exchange membrane (PEM) electrolyzer uses a polymer membrane as an ion conductor to produce hydrogen gas through the process of electrolysis. This type of electrolyzer is commonly used in a variety of applications, including fuel cell vehicles, renewable energy storage systems, and industrial processes. The major components of a PEM electrolyzer include a proton exchange membrane, electrodes, gas diffusion layers, and bipolar plates. The proton exchange membrane serves as the ion conductor, allowing protons to pass through while blocking electrons and other ions. The electrodes are typically made of a catalytic material, such as platinum, which promotes the electrochemical reactions that produce hydrogen. The gas diffusion layers help distribute the reactant gases evenly across the surface of the electrodes, and the bipolar plates serve as the current collectors and provide mechanical support for the electrolyzer.
The mechanism of operation of a PEM electrolyzer is based on the principles of electrolysis, where an electric current is passed through an electrolyte to produce chemical reactions at the electrodes. In a PEM electrolyzer, water is supplied to the electrolyzer and is split into its constituent elements, hydrogen and oxygen, at the electrodes. At the anode, oxygen is produced by the oxidation of water, and at the cathode, hydrogen is produced by the reduction of protons from the proton exchange membrane.