Abnormal infrared effects of nanometer scale thin film material of PtPd alloy in CO adsorption

Nanometer scale thin film material of PtPd alloy supported on glassy carbon (nm-PtPd/GC) was prepared by the electrochemical codeposition method under cyclic voltammetric conditions. STM patterns demonstrated that the prepared thin films are composed of layered crystallites in elliptic form. Electrochemicalin situ FTIRS studies explored the abnormal infrared effects (AIREs) of nm-PtPd/GC for CO adsorption, which are (i) the remarkable enhancement of IR absorption, (ii) the inversion of CO_ad band direction, and (iii) notable increase in the full width at half maximum (FWHM) of CO_ad bands. The results demonstrated also that the enhancement factor of IR absorption varies with the thickness of PtPd alloy film and has reached a maximum value of 38.3 under the experimental conditions.