Modeling the Chloride Ion Attack of Aluminum Oxide by XANES Analysis

Autor: Roeper, Donald F., O'Grady, William E., Natishan, Paul M.
Zdroj: ECS Transactions; April 2014, Vol. 58 Issue: 41
Abstrakt: This paper is a summary of previously published work. We have generated molecular simulations of Cl¯ located at different sites in several aluminum oxide models and carried out local l-projected density of states (LDOS) calculations to obtain the theoretical spectra. These are compared to our earlier experimental X-ray absorption near edge structure (XANES) data in order to study the interactions of chloride ions with the passive oxide film on aluminum as a function of electrochemical potential at the Cl K-edge. We show that the chloride first attacks the hydroxyl components of the aluminum oxide, penetrates the oxide film and finally attacks the metal surface. This has led to a number of new insights in the mechanism of the breakdown of the passive oxide film in chloride solutions.
Databáze: Supplemental Index