Electrolysis & PEMs: Positive Electrode, Negative Electrode, O2 Gas

[nuby]

How would a PEM work with a positive electrode, and negative electrode, with a PEM right between them within water.

Would O2 gas form on the membrane itself? How does this improve efficiency compared to the same cell without a PEM?

 

[Borek]

Write both electrode reactions.

 

[quicknote]

Electrolysis is a process in which an electric current is used to decompose a chemical compound, typically a liquid, into its constituent elements. In the case of water, this process involves splitting water molecules into hydrogen gas and oxygen gas. This process is facilitated by a device called a proton exchange membrane (PEM) electrolyzer.

A PEM electrolyzer consists of a positive electrode (anode), a negative electrode (cathode), and a PEM placed between them. The PEM is a thin, selectively permeable membrane that only allows protons (H+) to pass through, while blocking the passage of other molecules.

When an electric current is applied to the positive and negative electrodes, water molecules near the positive electrode are oxidized, releasing protons and oxygen gas. The protons then pass through the PEM and combine with electrons from the negative electrode to form hydrogen gas. Meanwhile, the oxygen gas produced at the positive electrode is released into the surrounding water.

The PEM plays a crucial role in this process by preventing the mixing of hydrogen and oxygen gases, which could potentially form an explosive mixture. Additionally, the PEM also helps to improve the overall efficiency of the electrolysis process. Without the PEM, the hydrogen and oxygen gases would mix together and recombine, reducing the amount of gas produced. The PEM also helps to maintain a higher concentration of protons near the negative electrode, which increases the efficiency of the hydrogen production reaction.

In summary, a PEM works with a positive electrode and a negative electrode by selectively allowing protons to pass through, while preventing the mixing of gases. This improves the efficiency of the electrolysis process and allows for the safe production of hydrogen gas. The PEM is an essential component in PEM electrolyzers and plays a vital role in the production of clean and sustainable energy.