Sulfide (H2S) 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 H₂S molecule at the Cr-doped iron (Fe(100)) surface. It is observed that H₂S 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 H₂S 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.