A Raman cell suitable for the study of solid/liquid/gas three-phase systems and that can work very efficiently onconfocal microprobe Raman systems was introduced. The influence of the environment on the adsorption behavior ofmodel molecule CO on Pt was investigated and different behaviors were observed in the aqueous solution compared tothe gas phase. A preliminary Raman measurement on the three-phase system was performed using methanol as a testingsolution. The diffusion of CO, a dissociate product of methanol, on the Pt electrode from the solution side to the gasside was observed.

The emphasis in the present study was placed on developing Raman spectroscopy into a versatile technique, whichoffers intriguing opportunities for investigating electrocatalytic reaction. Through the in-situ Raman spectroscopicstudy, with a confocal Raman microscope, on the methanol electrooxidation on platinum electrodes with varioussurface roughness, it has shown the advantage in obtaining the informative spectra during the surface reaction withhigh faradaic current. This is hard to be performed by the other spectroscopic methods that have to use the thin-layercell. The ability to obtain both the low frequency and the high frequency vibrations of Pt-C and C O bands allowsthe assignment of surface species unambiguously. The ease of studying the surface bonding, investigating highlyroughened surfaces with dark color and using high concentration electrolyte may provide a way to bridge the gapbetween the systems of fundamental research and practical applications. The results reveal the surface roughnesseffect on the electrooxidation process and provide clear evidence for the parallel oxidation mechanism.

A method to produce a substrate suitable for surface-enhanced Raman study on the pure massive Rh electrodewas developed. The surface-enhanced Raman scattering (SERS) active Rh electrode with good stability,reversibility, and ease of preparation can be obtained by the control-current electrochemical roughening method.The surface enhancement factor was estimated to be 3 orders of magnitude. Such kind of enhancement allowsthe investigation of not only some molecules of large Raman cross-section (e.g., pyridine) but also othermolecules of very small Raman cross-section (like CO). This result shows that the Rh surface can be used asa useful substrate for the combined electrochemical and Raman study of some systems that are both offundamental and application interest.

A detailed surface Raman study of the effect of the bulk concentration of cyanide (CN-), electrode potential.and immersion potential on the adsorption behavior of CN- on the Pt electrode surface was performed on aconfocal microprobe Raman system. The notable change of the C-N frequency and the Pt-C intensity at ca.-0.7 V(vs SCE) indicates a subtle change of the adsorption behavior of CN- on the platinum electrode insolutions with concentration of about 10-4M or lower. The concentration of cyanide in the bulk solutionaffects the adsorption behavior. The surface Raman signal can still be observed at concentrations as low as10-6M. When the CN-concentration is higher than 10-3M, the potential for immersing the platinum electrodein the CN-solution has a remarkable effect on the adsorption behavior of CN-With the high-quality surfaceRaman spectra, the surface enhancement factor for the adsorbed CN- was estimated to be about 150.