Characteristics and Electrochemical Reaction Kinetics of Polyaniline Nanofibers as a Promoter of Pt Electrode for Methanol Electrocatalytic Oxidation

The addition of La2O3 to an aniline polymerizing system to promote the formation of polyaniline nanofibers (PANT-La2O3) is herein demonstrated. The fiberization rate is significantly increased by the introduction of La2O3. Only trace amounts of lanthanum advantageously remain in the product, which therefore negligibly influence the electrochemical characteristics of the resulting polyaniline fibers. Research for the electrochemical reaction kinetics of PANI-La2O3 nanofiber indicates that the redox rate of polyaniline between leucoemeraldine and emeraldine is controlled by electron transfer and proton (H+) diffusion. The standard rate constants of the redox and the diffusion coefficients of H+ are measured at 20 degrees C. Cyclic voltammetric (CV) results indicate that PANI-La2O3 nanofibers are resistant against electrochemical degradation. Moreover, the modification of Pt electrode with PANI-La2O3 nanofibers promotes the efficiency of methanol electro-oxidation.