Pourbaix Diagram

In chemistry, a Pourbaix diagram, also known as a potential/pH diagram, Eh-pH diagram or a pE/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. Predominant ion boundaries are represented by lines. As such a Pourbaix diagram can be read much like a standard phase diagram with a different set of axes. But like phase diagrams, they do not allow for reaction rate or kinetic effects.

The diagrams are named after Marcel Pourbaix (1904–1998), the Russian-born, Belgian chemist who invented them.