Surface structures and electronic properties of SO2 adsorbed on Ni(111) and Ni(100) studied by S K-edge X-ray absorption fine structure spectroscopy

Interaction of SO2 with Oxygen on Ni(100) Studied by XPS and NEXAFS

“…Multilayer of SO 2 was prepared by doing 20 L of SO 2 on Ni(100) at 80 K. Chemisorbed SO 2 was produced by dosing 3 L of SO 2 at 80 K followed by annealing at 160 K. The NEXAFS features at 2473.2 eV and 2478.6 eV correspond to the transition of the sulfur 1s-electron to 3b 1 (π* resonance) and 9a 1 (σ* resonance) molecular orbitals of SO 2 , respectively. 2 The sulfur K-edge NEXAFS feature of chemisorbed SO 2 shows strong angular dependency. The π* resonance feature shows maximum intensity when the incident photon beam is glancing to the surface (Curve (C)).…”

“…This result agrees very well with the previous report. 2 The adsorption and surface reactions of SO2 on c(2x2)_O/ Ni(100) were also investigated by utilizing NEXAFS. Figure 3 shows the sulfur K-edge NEXAFS features of SO x species adsorbed on c(2x2)_O/Ni(100) at 160 K. The surface was prepared by exposing the c(2x2)_O/Ni(100) surface to 3 L of SO 2 at 80 K followed by annealing briefly at 160 K. It clearly shows three features at 2478.0 eV, 2480.0 eV, and 2482.4 eV.…”

“…Based on NEXAFS and SEXAFS studies, Yokoyama and co-workers reported that SO2 was chemisorbed on both Ni(100) and Ni(111) at ~170 K with its molecular plane parallel to the surface. 2 They also reported that the S atom directly interacted with substrate Ni, located at the bridge sites. The normal incident X-ray standing wave (NIXSW) technique study also showed that SO 2 was adsorbed molecularly on Ni(111) at 140 K with its molecular plane parallel to the surface but the S and O atoms were in off-atop sites.…”

Adsorption and Surface Reaction of SO2on Cu(100) Studied by S K-Edge XAFS and STM

“…The above results appear to be inconsistent to each other and further studies on the same system are needed. We have studied the surface structures of low coverage SOz on Ni(100),(110) and (111) at low temperature by the surface XAFS method and found that the SO2 molecules lie down flat on the surface with a slight S -0 bond elongation for all the cases [7,8]. These studies demonstrated the effectiveness of the surface XAFS method for surface adsorbate systems.…”

Adsorption Reaction of Amino Acid Molecule on Pd Thin Layer Surface Constructed by Nano-dots under Water Environment

“…To identify a chemisorbed adsorbate on each substrate surfaces, the assignation of NEXAFS peak positions is necessary. From the results of previous studies, we have judged the peak positions of L-cysteine thiolate and atomic S [2,8,12,13]. The spectra for L-cysteine aqueous solution and the NiAl(111) substrate without dipping into L-cysteine aqueous solution under dry environment are also shown as standard and background.…”