关键词: H2SO4, HClO4, Pt/GC, 甲酸氧化

Abstract: Influence of electrolyte on the electrocatalytic properties of Pt/GC electrodes for formic acid oxidation were studied by using cyclic voltammetry,SEM and electrochemical in situ FTIR spectroscopy.It has demonstrated that the surfaces of Pt/GC electrodes prepared in H2SO4 (Pt/GC1) or in HClO4(Pt/GC2) are all composed of platinum particles,but which crystals are some differences in size and shape.Diameters of platinum particles on the surface Pt/GC1 are of 100~200 nm,and with spheral shape in the majority.The sizes of platinum particles on the Pt/GC2 electrode are larger in general,part of particles is of cube shape and of diameter about 200 nm,and another part of particles is about 400 nm in diameter and of cauliflower shape.It has observed that all Pt particles are distributed relatively even on GC substrate.The results show that the electrocatalytic mechanism of formic acid oxidation on Pt/GC is similar to that on massive platinum,which involves two paths,i.e.one way through active intermediate and another through poison intermediate to CO2.It is flowed that the Pt/GC2 exhibits higher electrocatalytic activities than Pt/GC1.The electrodes ofPt/GC modified by Sb or Pb(Sb-Pt/GC or Pb-Pt/GC)are also prepared in the work.It is indicated that Sb-Pt/GC and Pb-Pt/GC enable not only to inhibit effectively the formation of poison intermediate CO,but also to increase significantly the electrocatalytic activity for oxidation of HCOOH through active intermediates.The electrocatalytic activities for seven electrodes to formic acid oxidation prepared in the current study are in the orders: Sb-Pt/GC2>Pb-Pt/GC2>Pb-Pt/GC1> Sb-Pt/GC1 >Pt/GC2>Pt/GC1>Pt.

Key words: H2SO4, HClO4, Pt/GC, HCOOH oxidationoxidation