核-壳结构Au-Pt纳米粒子的光谱表征和电催化性能

用化学还原法合成了核-壳结构Au-Pt纳米粒子.紫外可见光谱(UV-Vis)、电化学循环伏安(CV)和透射电子显微镜(TEM)表征结果指出，所合成的核-壳结构Au-Pt纳米粒子为球形，平均直径为27 nm.以CO为分子探针，结合透射红外光谱研究，发现CO以孪生吸附态形式(COT)吸附在Au-Pt纳米粒子上，在2110 cm－1和2063 cm－1附近分别给出对称和反对称红外吸收峰. CV研究结果指出Au-Pt/GC电极对CO的氧化有较高的催化活性，起始氧化电位较本体Pt电极提前了0.45 V，峰电位提前了0.11 V.

Spectroscopic Characterization and Electrocatalytic Properties of Core-Shell Au-Pt Nanoparticles

Core-shell Au-Pt nanoparticles were synthesized by chemical reduction method.The mean diameterof the nanoparticles was determined to be 27 nm by transmission electron microscope(TEM).The preparednanoparticles were characterized by ultraviolet-visible(UV-Vis)and infrared transmission spectroscopy.Thedisappearance of the characteristic peak near 520 nm of Au nanoparticles in UV-Vis spectroscopy confirmed theformation of the core-shell structure.Using infrared transmission spectroscopy,the geminal CO adsorbates thatyielded a doublet IR band at around 2110 cm~(-1) and 2063 cm~(-1) on core-shell Au-Pt nanoparticles were detectedfor the first time.The core-shell Au-Pt nanoparticles supported on GC(glassy carbon)substrate as electrodeexhibited good electrocatalytic properties for the oxidation of adsorbed CO(CO_(ad))species.The onset and peakpotentials of CO_(ad) oxidation were negatively shifted 0.45 and 0.11 V,respectively,in referring to the valuesmeasured on a bulk Pt electrode.