Adsorption and diffusion of sulfur on the (111), (100), (110), and (211) surfaces of FCC metals: Density functional theory calculations

Abstract

We have studied the adsorption and diffusion of sulfur at the low-coverage regime of 0.25 ML on the (111), (100), (110), and (211) surfaces of Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au using density functional theory calculations. Sulfur adsorbed preferentially on threefold or four-fold high-coordination sites over most of the studied surfaces. On the Ir(110), Pt(110), and Au(110) surfaces, sulfur is more stable on the twofold sites. Calculations of the minimum energy diffusion pathway show that the energy barrier for the surface diffusion of sulfur depends on the orientation and nature of the metal surfaces. On the (100), sulfur shows the highest diffusion energy, ranging from 0.47 eV in Au(100) to 1.22 eV in Pd(100). In the (110) surface, the diffusion of sulfur is along the channel for Ni, Cu, Rh, Pd, and Ag, and across the channel for Ir, Pt, and Au. In the case of the (211) surfaces, the diffusion is preferentially along the terrace or step-edge sites. Our work provides data for the adsorption of sulfur on many surfaces not previously reported. The present work is a reference point for future computational studies of sulfur and sulfur-containing molecules absorbed on face center cubic metal surfaces.

Sulfur adsorption on coinage metal(100) surfaces: propensity for metal–sulfur complex formation relative to (111) surfaces

“…A recent DFT study of S adsorption on lowindex surfaces considered not just coinage metals, but also Ni, Pd, Pt, Rh, and Ir. 29 In all cases, adsorption on the (100) surface is stronger than on the (111) surfaces, although the difference is much smaller for Au than all other metals (consistent with the results reported above). Ref.…”

Hybrid Organic‐Inorganic Heterogeneous Interfaces for Electrocatalysis: A Theoretical Study of CO2 Reduction to C2

“…Aminothiolates preferentially adsorb at the four-fold hollow on Cu(100), threefold hollow on Cu(111) and step-bridge site over Cu(211), respectively, at various examined coverages (i. e., 1/16 ML, 1/8 ML, 1/4 ML) (Figures S2-S4 and Table S1), which is consistent with the previous study. [14] All three Cu facets have very similar strong binding energies for aminothiolates (i. e., lower than À 2 eV, Figure S5). As increasing the surface coverage of aminothiolates to 1/2 ML, Cu(100) shows the strongest adsorption energies of ~À 1.7 eV (~À 1.3 eV over Cu(211) and À 0.6 eV over Cu(111)).…”

Surface specificity and mechanistic pathway of de-fluorination of C60F48 on coinage metals

“…26 It is likely that full de-uorination would imply molecular rotation (see simulations below), therefore this difference may arise from differences in the energy barrier for surface diffusion the molecules, lower on (111) than on (100) surfaces. 46 In principle, only C 60 F 48 interacting with uncovered copper turns into C 60 and, therefore, as the substrate surface is being covered the reaction would cease. This hypothesis was veried by elemental sensitive XPS.…”