ALGORITHM FOR COMPUTER-AIDED CONSTRUCTION OF THE POTENTIAL-pH DIAGRAMS OF METAL-ION-WATER SYSTEMS AND ITS APPLICATION TO THE CORROSION IN IODINE-IODIDE SOLUTION.

Abstract

An algorithm to construct the potential-pH diagram of metal-ion-water systems by using a computer was established and it is applied to the metal-iodine-water system to explain the corrosion behavior of metals in the environment corresponding to the first stage reaction of the Magnesium-Iodine Cycle of thermochemical hydrogen production process. It is concluded that Ta, Zr, and Ti are thermodynamically protected owing to the oxide films which are more stable than iodides considered. On the contrary, noble metals such as Au, Ag, and Pt are predicted to corrode in concentrated iodine-iodide solution. Thermodynamic prediction is in fairly good agreement with the experimental results reported before.