In situ chemical fabrication of polyaniline/multi-walled carbon nanotubes composites as supports of Pt for methanol electrooxidation

In this study, platinum (Pt)-polyaniline(PANI)/MWNTs catalysts were synthesized by two sequential reactions. First, core-shell structural PANI/MWNTs composites were fabricated by in-situ chemical oxidation polymerization, in which MWNTs act as the core and PANI as the shell. Then, Pt particles were deposited on the PANI/MWNTs composites by a chemical reduction method. The morphology and constitution of the products were characterized by FT IR, scanning electron microscopy, transmission electron microscopy and XRD. It was observed that the Pt particles were smaller in size and more uniformly distributed on these composite supports than those on the reference, pure MWNT supports. XRD results showed higher Pt(111) content in the catalyst deposited on PANI/MWNTs supports than that on MWNTs. The cyclic voltammeter (CV) tests demonstrated that the electrode modified by Pt-PANI/MWNTs ternary composite catalyst showed a higher catalytic stability than Pt-MWNT binary catalyst did, due to the synergic interaction between Pt and the composite support.