Abstract: An individually addressable array of Pd microelectrodes was combined with in situ microscope FTIR reflection spectroscopy in the current paper to carry out surface combinatorial studies. Pd film of different nanostructures on the array was prepared electrochemically by applying the method of square wave potential. The electrochemical behavior and surface structure of the Pd film were investigated respectively by using cyclic voltammetry and scanning electron microscopy. It revealed that, through the surface combinatorial studies, with the increase of treatment time of the square wave potential, the spectral IR characteristics of bridge bonded CO on the array was transformed successively from normal absorption band to Fano-like spectral line shape, and finally to abnormal IR features. The results demonstrate that the anomalous IR properties of Pd thin film depend strongly on the nanostructure of the film.

Key words: Pd microelectrodes array, Nanostructured films, In situ microscope FTIR spectroscopy, Surface combinatorial electrochemistry, Abnormal infrared effects