Abstract:
NEXAFS and FT-RAIRS have been used to investigate the adsorption of CO and CO2 on ZnO(<000(1)over bar>)-O and its modification by copper overlayers. NEXAFS data indicate a CO32- species with the molecular plane within 30 degrees of the surface normal following CO and CO2 adsorption on the clean surface at 130 K. Upon low-temperature deposition of a submonolayer Cu film, CO32- species were no longer formed following CO adsorption, although molecular CO was evidenced with the molecular axis within 20 degrees of the surface normal. A single v(CO) band observed in FT-RAIRS indicates that the CO is adsorbed on 2D Cu(110)-like sites in an atop position. Preannealing the Cu him to 400 K led to a redistribution of Cu into 3D islands, as evidenced by FT-RAIRS. Exposure to CO of such a surface at 130 K resulted in both CO and CO32- formation. This suggests that Cu initially nucleates at the active sites for CO32- formation on ZnO(<000(1)over bar>)-O which are uncovered during the onset of 3D island growth.

Addresses:
GutierrezSosa A, UNIV MANCHESTER, INTERDISCIPLINARY RES CTR SURFACE SCI, MANCHESTER M13 9PL, LANCS, ENGLAND.
UNIV MANCHESTER, DEPT CHEM, MANCHESTER M13 9PL, LANCS, ENGLAND.
UNIV LIVERPOOL, INTERDISCIPLINARY RES CTR SURFACE SCI, LIVERPOOL L69 3BX, MERSEYSIDE, ENGLAND.
UNIV WASHINGTON, DEPT CHEM, BG 10, SEATTLE, WA 98195.

Publisher:
ROYAL SOC CHEMISTRY, CAMBRIDGE

IDS Number:
XR684

ISSN:
0301-7249