Elucidating the role of extended surface defects at Fe surfaces on CO adsorption and dissociation

The adsorption and dissociation of hydrocarbons on metallic surfaces during catalytic reactions in a steam reforming furnace often lead to the carburization of the catalysts and metallic surfaces involved. This process is greatly accelerated by the presence of intrinsic defects like vacancies and grain boundaries and is succeeded by surface to subsurface diffusion of C. We employ both density functional theory and reactive force field molecular dynamics simulations to investigate the effect of surface defects on CO dissociation rate directly related to metal dusting corrosion. We demonstrate that stable surface vacancy clusters with large binding energies accelerate the adsorption of CO molecules by decreasing the corresponding dissociation energies. In addition, we demonstrate that the appearance of multiple GBs at the surface leads to an enhancement of the CO dissociation rate. Furthermore, we demonstrate that the increase in surface roughness by emerging GBs leads to an increase in CO dissociation rate. •Adsorption and dissociation of hydrocarbons on metallic surfaces during catalytic reactions often lad to carburization of metal catalysts and the metal surfaces in steam reforming furnaces.•Intrinsic defects such as vacancies and grain boundaries on the surface greatly accelerate the carburization process, followed by surface-to-subsurface diffusion of C.•Both density functional theory (DFT) and ReaxFF molecular dynamics (MD) simulations are used to investigate the impact of surface topology on the dusting corrosion rate.•We demonstrate that a surface with vacancy cluster and multiple GBs emerging at the surface dramatically enhance the dissociation rate of CO.