Preparation of Pt/poly(pyrogallol)/graphene electrode and its electrocatalytic activity for methanol oxidation

Graphene (RGO) can catalyze the electrochemical oxidative polymerization of pyrogallol in the acidic solution to form poly(pyrogallol) (PPG) that has oxygen-containing functional groups in the polymer chain and a rapid charge transfer ability. Pt particles are deposited on the bare glassy carbon (GC). PPG/GC, and PPG/RGO/GC electrodes, respectively, at a constant potential of -0.20 V or -0.25 V (vs. SCE). The sizes of the Pt particles are affected by the electrodeposition potential of Pt and the kinds of the electrode material. Both PPG and graphene play an important role in improving Pt particle dispersion and suppressing the agglomeration of Pt particles. The electrocatalytic efficiency of the Pt electrodes toward methanol oxidation is affected by the amount of Pt deposited on the electrode, sizes of Pt particles and the kinds of the electrode material. Under the same electrodeposition potential and the same amount of Pt deposited on the electrode, the order of the electrocatalytic efficiency of the three kinds of the electrode is as follows: Pt/PPG/RGO/GC > Pt/PPG/GC > Pt/GC. On the basis of the I-f/I-b ratio on cyclic voltammograms, the catalyst tolerance to CO poisoning is improved by PPG and graphene at the initial stage of methanol oxidation. (C) 2011 Elsevier B.V. All rights reserved.