Core shell like behavior of PdMo nanoparticles on multiwall carbon nanotubes and their methanol oxidation activity in alkaline medium

Core–shell like behavior has been shown by the nanoparticles comprised of Pd and Mo that have been synthesized on multiwall carbon nanotubes (Mo@Pd/MWCNT or Pd@Mo/MWCNT) by hydrothermal technique in different pH. The synthesized catalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The formation mechanism of the core–shell like PdMo nanoparticles has been explained with the consequences of reduction potential and surface segregation properties of Pd and Mo. The activity of the catalysts towards methanol oxidation is investigated by cyclic voltammetry (CV), chronoamperometry and impedance spectroscopy. The primary electrochemical analysis indicates that the electrochemical activity of this Pd@Mo/MWCNT along with Mo@Pd/MWCNT is better than that of Pd/MWCNT.

► Core shell like PdMo nanoparticles form on multi wall carbon nanotubes. ► Methanol oxidation reaction is more favorable on Mo@Pd and Pd@Mo than Pd. ► Amount of Mo is the key to get the optimum performance. ► Forward peak current density of Mo@Pd/MWCNT (pH∼9) was 395.61 mAcm−2mg−1Pd.