CS AND CO COADSORBED ON RU(0001) - LOW-ENERGY-ELECTRON DIFFRACTION ANALYSIS

被引:16
作者
OVER, H
BLUDAU, H
KOSE, R
ERTL, G
机构
[1] Fritz-Haber-Institut der Max-Planck Gesellschaft, Faradayweg 4-6
关键词
ALKALI METALS; CARBON MONOXIDE; LOW ENERGY ELECTRON DIFFRACTION (LEED); LOW INDEX SINGLE CRYSTAL SURFACES; RUTHENIUM; SURFACE STRUCTURE;
D O I
10.1016/0039-6028(95)00221-9
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The adsorption of CO on a precovered Cs(2 X 2)-Ru(0001) structure (theta(Cs) = 0.25) leads to the formation of two distinct (2 X 2)-Cs-CO phases with one and two CO molecules in the unit cell, respectively. The LEED structure analyses showed that Cs remains in the on-top position while CO resides in the hcp position for CO coverage below 0.25 and subsequently fills up the fee sites. Compared to the clean CO-(root 3 X root 3)R30 degrees surface, the CO molecule switches its adsite from being on-top to threefold hollow under the influence of coadsorbed Cs. The CO axis is oriented normal to the surface; no tilting has been found. In addition to the short-range interaction, the electrostatic (long-range) attraction between Cs and CO is manifested by the island growth observed for Cs coverages below 0.25 down to 0.08.
引用
收藏
页码:62 / 68
页数:7
相关论文
共 25 条
[1]   DIRECT MEASUREMENT OF POTASSIUM-PROMOTED CHANGE IN HEAT OF ADSORPTION OF CO ON NI(100) [J].
ALSARRAF, N ;
STUCKLESS, JT ;
KING, DA .
NATURE, 1992, 360 (6401) :243-245
[2]  
BLUDAU H, UNPUB
[3]  
BONZEL HP, 1993, CHEM PHYSICS SOLID S, V6
[4]  
BOWKER M, 1981, SURF SCI, V108, P299
[5]   MODELING THE POTASSIUM PROMOTION OF CO BONDING TO NI(100) [J].
CHRISTENSEN, OB ;
NORSKOV, JK .
CHEMICAL PHYSICS LETTERS, 1993, 214 (05) :443-446
[6]  
GIERER M, UNPUB
[7]   THE INTERACTION RANGE IN ALKALI METAL-PROMOTED SYSTEMS [J].
HESKETT, D .
SURFACE SCIENCE, 1988, 199 (1-2) :67-86
[8]   A NEAR-EDGE X-RAY ABSORPTION FINE-STRUCTURE AND PHOTOELECTRON SPECTROSCOPIC STUDY OF THE STRUCTURE OF ACETYLENE ON PD(111) AT LOW-TEMPERATURE [J].
HOFFMANN, H ;
ZAERA, F ;
ORMEROD, RM ;
LAMBERT, RM ;
YAO, JM ;
SALDIN, DK ;
WANG, LP ;
BENNETT, DW ;
TYSOE, WT .
SURFACE SCIENCE, 1992, 268 (1-3) :1-10
[9]  
HRBEK J, 1985, SURF SCI, V164, P139, DOI 10.1016/0039-6028(85)90704-6
[10]   ADSORBATE-INDUCED ELECTRONIC MODIFICATION OF ALKALI-METAL OVERLAYERS [J].
JACOBI, K ;
SHI, H ;
GRUYTERS, M ;
ERTL, G .
PHYSICAL REVIEW B, 1994, 49 (08) :5733-5736