Adsorption Behavior of CO at the Ultrathin Rh and Pt Film Electrodes

摘要

Pt group metals have been widely used in catalysis such as hydrogenation of organic compounds and carbon monoxide oxidation. The information about CO adsorption on the Pt group surfaces and the influence of the other normal existed surface species, such as hydrogen and CO_2, will be greatly helopful to elucidate the adsorption behavior of CO on Pt group metal surfaces and get a deeper understanding of their catalytic mechanisms. Surface-enhanced Raman spectroscopy (SERS) has become an increasingly important means to characterie the electrochemical metal-solution interface over the past two decades. Our laboratory has successfully obtained SERS from neat transition metal surfaces, including Pt, NI and Co. We are able to observe SERS of CO and atop adsorbed H on roughened Pt surfaces~(1). However, compared with Ag, Au and Cu which exhibit great surface enhancement, the signals of these adsorbates with very small Raman cattering cross sections are still too weak to be studied in detail for most pure transition metals.