Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (05): 441-444.doi: 10.3866/PKU.WHXB20030513

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Electrocatalytic Properties of Agglomerates of Pt Nanoparticles in Methanol Oxidation

Chen Wei;Sun Shi-Gang;Si Di;Chen Sheng-Pei   

  1. State Key Laboratory for Physical Chemistry of Solid Surfaces,Department of Chemistry,Xiamen University,Xiamen 361005
  • Received:2002-09-27 Revised:2003-01-12 Published:2003-05-15
  • Contact: Sun Shi-Gang

Abstract: Agglomerates of Pt nanoparticles were synthesized by using H2 as reduction reagent and nafion as stabilizer. The electrode of agglomerates of Pt nanoparticles was prepared by dispersing the agglomerates onto glassy carbon surface and is denoted as Ptnag/GC.The average size of the agglomerates in colloid and on the surface of electrode were characterized to be around 400 nm using TEM and SEM, respectively. Cyclic voltammetry and in situ FTIR spectroscopy were employed to study electrocatalytic properties of the Ptnag/GC electrode towards methanol oxidation. It has been revealed that the agglomerates of Pt nanoparticles exhibit significant electrocatalytic activity for the oxidation of CH3OH.In comparison with CH3OH oxidation on an electrode of Pt thin film supported on Au, the oxidation potential has been shifted negatively about 300 mV on the Ptnag/GC. The results demonstrated also that the oxidation of CH3OH is a complex process, which may be influenced by the diffusion of CH3OH and controlled by the oxidation-reduction of the agglomerates of Pt nanoparticles on electrode surface. Linearly adsorbed CO species (COL) is the only intermediate that has been determined by in situ FTIR spectroscopy. The IR features of COL illustrated that the agglomerates of Pt nanoparticles exhibit abnormal infrared effects as other kind low-dimensional nanomaterial does.

Key words: Agglomerates of Pt nanoparticles, Methanol, Electrocatalytic oxidation