Fabrication of Pd/TiO2-multiwall carbon nanotubes catalyst and investigation of its electrocatalytic activity for formic acid oxidation

Abstract

In this study, a novel Pd/TiO2-MWNTs catalyst is synthesized by a unique chemical method. The pretreated TiO2 nanoparticles are applied as support materials between Pd nanoparticles and functional multiwall carbon nanotubes (MWNTs) template. The morphology and physicochemical properties of the catalysts are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It is observed that the functional MWNTs are partially covered by TiO2 nanoparticles, and that the metallic Pd nanoparticles are homogeneously deposited onto the TiO2 nanoparticles with smaller sizes compared with those of Pd/MWNTs. The electrocatalytic activity of the Pd/TiO2-MWNTs is investigated by cyclic voltammetry and chronoamperometry measurements in 0.5 M H2SO4 and 1 M HCOOH acidic solution, respectively. Results indicate that the introduction of pretreated TiO2 into the nanocomposite highly improves its electrocatalytic activity, durability, and stability. Thus, the Pd/TiO2-MWNTs catalyst is expected to be an effective electrode material for formic acid oxidation.