Theoretical and Experimental Research on the Adsorption Performance of Hydrogen Sulfide on the Surface of Stainless Steel

In this paper, the macro-surface and SEM micro-surface of stainless steel were studied, and the absorption curve of stainless steel to H 2 S was tested at first. Then, the geometric structure based on the first-principles calculation method of DFT was optimized and the adsorption of H 2 S molecules on the surface of stainless steel was calculated. H 2 S molecules could be spontaneously adsorbed to the surface of different types γ -Fe(111). H 2 S molecules could dissociate and adsorb owing to the vacancy defects, because the S–H bond in H 2 S would break at the vacancy site. The absolute value of the adsorption energy was high, so the adsorption amount of H 2 S was larger. H 2 S would preferentially adsorb to vacancy defect positions. However, due to the limited number of vacancies, H 2 S would gradually adsorb to other positions. While H 2 S molecules were adsorbed in a molecular state, dissociative adsorption was also proceeding. The absolute value of the adsorption energy was higher and the adsorption with the substrate was stronger. Moreover, the existence of vacancy defects would facilitate the dissociative adsorption of H 2 S molecules.