What kind of anode is typically used for cathodic protection?

Cathodic protection is a technique used to control corrosion of a metal surface by making it the cathode of an electrochemical cell. To achieve this, sacrificial anodes are typically utilized. These anodes are made from a more reactive metal that will corrode preferentially, thereby protecting the underlying metal structure.

When a sacrificial anode is attached to a metal hull or structure, it serves as the anode in the electrochemical cell, sacrificing itself to prevent the corrosion of the protected metal. The electrochemical reaction drives the electrons away from the structure (the cathode) and towards the anode (the more reactive sacrificial material). This process is effective in marine environments where metals, such as steel, are prone to corrosion due to their exposure to water and electrolytes.

While impressed anodes and passive anodes can also be used in certain cathodic protection systems, they generally do not function in the same manner as sacrificial anodes. Impressed anodes require an external power source, and passive anodes (which are not actively corroded) do not provide the same level of protection as sacrificial anodes, especially in marine systems. Ferrous anodes, which are made from iron, would generally not be