Effect of Impurity Atoms on the Adsorption/Dissociation of Hydrogen Sulfide and Hydrogen Diffusion on the Fe(100) Surface

Jingxuan Liang; Xiangli Wen; Shikai Wei; Shuqi Zheng

doi:10.1021/acsomega.1c01946

Effect of Impurity Atoms on the Adsorption/Dissociation of Hydrogen Sulfide and Hydrogen Diffusion on the Fe(100) Surface

ACS Omega. 2021 May 28;6(22):14701-14712. doi: 10.1021/acsomega.1c01946. eCollection 2021 Jun 8.

Authors

Jingxuan Liang¹, Xiangli Wen^{1

2}, Shikai Wei¹, Shuqi Zheng¹

Affiliations

¹ State Key Laboratory of Heavy Oil Processing, Department of Materials Science and Engineering, China University of Petroleum (Beijing), Beijing 102249, PR China.
² State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, PR China.

Abstract

In the actual environment, impurity atoms significantly affect the adsorption/dissociation of gas molecules on the substrate surface and in turn promote or impede the formation of subsequent products. In this study, we investigate the effects of three kinds of impurity atoms (H, O, and S) on the adsorption/dissociation of hydrogen sulfide (H₂S) and hydrogen (H) diffusion processes by using the density functional theory method. We found that impurity atoms can change the charge density distribution of the surface and thus affect the adsorption/dissociation process of H₂S. The existence of a H atom reduces the dissociation barrier of H₂S. The adsorption site of H₂S near the O atom is transferred from the bridge site to the adjacent top site and the first-order dissociation barrier of H₂S is 0.07 eV, which is prominently lower than that of the pristine surface (0.28 eV). The presence of a S atom transfers the adsorption site of H₂S to a farther bridge site and effectively affects the dissociation process of H₂S. Both O and S atoms hinder the dissociation process of HS. Moreover, the diffusion process of H atoms to the subsurface can be slightly impeded by the O atom. Our work theoretically explains the influence mechanism of impurity atoms on the adsorption/dissociation of H₂S and H diffusion behavior on the Fe(100) surface.