Electrocatalytic oxidation of CO on gold nanoparticles assembled on bulky noble metal substrates

Gold nanoparticles (AuNPs) have been successfully deposited on bulky gold and platinum electrodes by a self-assembly method, and the electrocatalytic activity of AuNPs has been studied in detail by cyclic voltammetry in a CO saturated alkaline solution. The experimental results show that, compared with bulky gold, the AuNPs assembled both on Au and Pt electrodes exhibit well-distinguishable electrocatalyic activity toward CO. This is the first report about the electrocatalytic oxidation of CO on gold nanoparticles with a diameter larger than 10 nm. Furthermore, the effect of gold oxides on the electrocatalytic activity of AuNPs has been investigated. It was shown that formation of a gold oxide layer on the surface of AuNPs was one of the key steps for the electrocatalytic oxidation of CO on Au and Pt supported gold nanoparticles. For AuNPs with the same diameter, the more the amount of gold oxide on their surface, the higher the electrocatalytic activity for CO oxidation.