INDUCED ORDERING OF ETHYLIDYNE ON THE PD(111) SURFACE BY THE PREADSORPTION OF OXYGEN - A LEED AND HREELS STUDY

被引：21

作者：

NASCENTE, PAP ^{[1
]}

VANHOVE, MA ^{[1
]}

SOMORJAI, GA ^{[1
]}

机构：

[1] UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720

来源：

SURFACE SCIENCE | 1991年 / 253卷 / 1-3期

关键词：

D O I：

10.1016/0039-6028(91)90590-O

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：

Overlayers of oxygen coadsorbed with acetylene and ethylene on a Pd(111) surface were studied by low-energy electron diffraction (LEED) and high-resolution electron-energy-loss spectroscopy (HREELS) in the temperature range 150-320 K. Low temperature adsorption of both C2H2 and C2H4 resulted in non-dissociatively chemisorbed molecules, and the preadsorption of oxygen did not change the LEED or HREELS data. At room temperature both C2H2 and C2H4 formed ethylidyne (C2H3), which poorly ordered in a (square-root 3 x square-root 3)R30-degrees structure. We found that preadsorption of oxygen induced better ordering for C2H3 formed from acetylene exposure, but not for C2H3 derived from ethylene adsorption. We propose that preadsorbed oxygen helped the ordering of the C2H3 overlayer by: (a) efficiently removing surface hydrogen and (b) attractively interacting with C2H3 to give coadsorbate induced ordering.

引用

页码：167 / 176

页数：10

共 57 条

[1] LEED AND HREELS STUDIES OF THE COADSORBED CO + ETHYLIDYNE AND NO + ETHYLIDYNE SYSTEMS ON THE RH(111) CRYSTAL-SURFACE [J].