(452e) Dissolution of a Platinum Catalyst in Acid Medium: Density Functional Theory Study

We investigate the thermodynamic properties of the elementary reactions which may determine dissolution of Pt and other metals in acid medium. The dissolution mechanism is based on the analysis of the Gibbs free energies of reaction as given by DFT calculations, and ab initio MD is used to further investigate details of the mechanism of thermodynamically favorable dissolution reactions. The results indicate that the dissolution processes in acidic environment are electrochemical instead of chemical processes and possible elementary reactions are proposed. Factors which influence the dissolution are also investigated such as electrode potential, metal species and different alloy compositions.