| The main purpose of the present work is to investigate dissociative andadsorption of clhanol at roughcncn plalinm and Pt-Ru electrodes, to devise a simple and efficient measure to synthesize platinum-based nano-electrocatalysts and prepare the Pt-based nanoparticles modified GC electrode. The electro-catalytic behavior of some organic molecules such as formic acid, methanol and CO at these Pt-based electrodes was studied and Surface Enhanced Raman spectroscopy (SERS) was extended to investigate the electro-catalytic behavior of organic small molecules on Pt-based nanoparticles supported GC surface. Their structure, size, optical and electronic properties were systematically characterized and estimated by TEM, XRD, SAED, UV-Visible, AFM. These electro-catalytic and SERS behaviors of organic small molecules was investigated by combining conventional electrochemical methods with Surface Enhanced Raman spectroscopy (SERS). The thesis mainly consists of the following four parts:1. The behaviors of adsorption and oxidation of ethanol on a roughening platinum electrode with high activity of SERS were studied by using cyclic voltammetry and in-situ surface enhanced Raman spectroscopy because of the key roles of in the direct alcohol fuel cell (DAFC). The effect of the roughened factor, the initial concentration of ethanol, the electrode potential on dissociative adsorption of ethanol in an acid solution were systematically discussed by carefully designing potential programme. Assisted by the highly sensitive confocal microprobe Raman spectrometer and proper surface roughening procedure, surface Raman spectra of dissociative adsorption of ethanol on Pt electrode were obtained for the first. The investigation also shows that pH and electrolytes have a marked influence on the dissociative adsorption of ethanol on the roughening platinum surface. It were firstly found that ethanol can be self-dissociated to produce poisoning intermediate CO at least, which discourage the further oxidation of ethanol, some information of Pt-C and Pt-C-Pt stretching vibration from linearly -adsorbed and bridged-adsorbed CO located in low frequency were examined, respectively. The investigation also shows that the electro-oxidationof ethanol on the roughened platinum was a diffuse-controlled reaction in sulfuric acid. The interesting conversion of bridged adsorbed CO to linearly-bonded CO from dissociation of ethanol was also observed in a base medium when the electrode potential was changed. By correlating the in-situ SERS date with the electrochemical dates, it was found that the oxidation of ethanol was processed via the parallel mechanism. It is especially noticed that this part also extends SERS to the electrocatalytic fields of C2 organic molecules.2. Two different kinds of Pt-Ru electrode were prepared by depositing Ru on the roughened Pt electrode surface and co-depositing Pt and Ru at the smooth glassy carbon (GC) electrode, respectively. The SERs of ethanol and formic acid at the roughened Pt-Ru electrode were firstly obtained for the first time. The result showed that the presence of Ru could enhance the electro-catalytic activities in electrooxidation of ethanol and formic acid. The coverage of Ru was concisely discussed by using CV, I-t curves and SERS. The presence of Ru-O peaks of CV in sulfuric acid and Raman spectra at -600 cm-1 help to argue for the bi-function mechanism. The observations of signals of strongly adsorbed CO and active intermediates located at -1380 cm-1 from HCOOH electrooxidation further to confirm that the oxidation of formic acid on Pt-Ru/GC was processed via the parallel mechanism.3. Aucore-Ptshell nanoparticles with well-dispersed and controllable size (20-150 nm) were synthesized by using a seed-induced approach, and these nanoparticles were also assembled on GC electrode surface to fabricate Aucore-Ptshell/GC electrode whose electrochemical behavior was similar to that of the roughened Pt electrode. The results shows that the ways of CO adsorbed on Aucore-Ptshell/G...
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