Experimental and Theoretical Surface Core Level Shift Study of the S-Rh(100) Local Environment

详细信息    查看全文

• 作者：Laura Bianchettin ; Alessandro Baraldi ; Erik Vesselli ; Stefano de Gironcoli ; Silvano Lizzit ; Luca Petaccia ; Giovanni Comelli ; Renzo Rosei
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：March 15, 2007
• 年：2007
• 卷：111
• 期：10
• 页码：4003 - 4013
• 全文大小：764K
• 年卷期：v.111,no.10(March 15, 2007)
• ISSN：1932-7455

文摘

The local changes of the Rh(100) electronic structure induced by sulfur adsorption at different coverage havebeen investigated by combining high-energy resolution core level photoemission spectroscopy, low-energyelectron diffraction, Monte Carlo simulations, and ab initio calculations. Our results show that upon adsorptionthe local density of states does not change appreciably beyond the next neighbors, thus supporting the conclusionthat the well-known catalyst's sulfur poisoning effect cannot be related to electronic structure long-rangemodifications. We also find that the sulfur-induced Rh 3d_5/2 component originated by the second layer Rhatoms below the sulfur adsorbate shifts by as much as -235 meV with respect to deeper layer contributions.This result points out the importance of considering the contribution of subsurface atoms in the overall 3d_5/2core-level line shape of transition metal surfaces. Ab initio calculations allow a detailed quantitativeunderstanding of the measured core level shifts. Possible mechanisms that explain the observed core levelshifts are discussed.