Sulfide (H 2 S) Corrosion Modeling of Cr-Doped Iron (Fe) Using a Molecular Modeling Approach.

This work presents the use of density functional theory to study the adsorption/dissociation mechanism of the H 2 S molecule at the Cr-doped iron (Fe(100)) surface. It is observed that H 2 S is weakly adsorbed on Cr-doped Fe; however, the dissociated products are strongly chemisorbed. The most feasible path for disassociation of HS is favorable at Fe compared to Cr-doped Fe. This study also shows that H 2 S dissociation is a kinetically facile process, and the hydrogen diffusion follows the tortuous path. This study helps better understand the sulfide corrosion mechanism and its impact, which would help design effective corrosion prevention coatings.