Au@Pt纳米粒子催化O2还原反应的电化学研究

摘要

Core-shell nanostructure Au@ Pt nanoparticles were synthesized with a diameter of 100 nm Au nan-oparticles as cores, ascorbic acid as reducing agent and H2PtCl6 · 6H20 as the precursor. The synthesized nanoparticles and commercial electrocatalysts were dropped on glassy carbon electrodes (Au@ Pt/GC) to form the oxygen reduction electrodes(Au@ Pt/GC, Pt/C/GC). The reaction activities for oxygen reduction and methanol tolerance of Au@ Pt/GC and commercial Pt/C/GC electrodes were compared with those of rotating disk electrode and other conventional electrochemical methods. At a significantly reduced amount of Pt, the oxygen reduction activity of Au@ Pt nanoparticles is still comparable with the commercial Pt/C. The oxygen reduction proceeds via a four-electron transfer reaction to water on Au@ Pt nanoparticles. Futhermore, it shows a good tolerance to methanol.%以100 nm的Au粒子为核,抗坏血酸为还原剂,H2PtCl6·6H2O为前驱体,合成了Pt包Au核壳结构纳米粒子( Au@ Pt)及其修饰的玻碳(GC)电极(Au@ Pt/GC).采用旋转圆盘电极等常规电化学方法,比较了Au@ Pt/GC和商用碳载铂(Pt/C)修饰的玻碳电极(Pt/C/GC)催化O2还原反应活性及耐甲醇性能,发现Au@ Pt纳米粒子在铂用量很低的情况下,其催化O2还原反应活性仍与商用Pt/C相当,而且还具有优良的耐甲醇性能；其催化O2还原反应机理按O2直接还原成H2O的四电子历程进行.