Infrared Reflection Absorption Study for Carbon Monoxide Adsorption on Chromium Deposited Cu(100) Surfaces

This study investigates carbon monoxide (CO) adsorption and desorption behaviors on 0.1-0.6-mm-thick Cr-deposited Cu(100) surfaces using infrared reflection absorption (IRRAS) and temperature-programmed desorption (TPD) spectroscopic methods. Tire low-energy electron diffraction (LEED) pattern for the 0.1-nm-thick Cr-deposited Cu(100) surface indicates that distorted bcc-Cr(110) grows on fcc-Cu(100). The CO exposure to a clean Cu( 100) at 90 K produces a single and Sharp IR absorption hand at 2090cm(-1) that is attributable to adsorbed CO on the on-top site of the Cu atoms' on the surface. Two absorption bands are located at 2085 and 2105cm(-1) on the IRRAS spectrum for the CO-saturated 0.1-mm-thick Cr/Cu(110) surface. The former might originate from linearly hooded CO on the uncovered Cu substrate surface. with increasing Cr thickness, the latter high-frequency hand becomes prominent. For the 0.3-nm-thick Cr surface, the band at 21 17 cm(-1) dominates all spectra through CO exposure. The TPD spectra of the Cr-deposited Cu surfaces show two remarkable features at 220-250 and 320-390 K. which are ascribable respectively to Cu-CO and Cr-CO bonds, Lower desorption Peaks shift to higher temperatures with increasing Cr thickness. Based on TPD and IRRAS results. adsorption-desorption behaviors of CO on the Cr-deposited Cu(100) surfaces are discussed herein. [doi: 10.2320/matertrans.MRA2008442]