Efficient Anchorage of Palladium Nanoparticles on the Multi-Walled Carbon Nanotubes as Electrocatalyst for the Hydrazine Electrooxidation in Strong Acidic Solutions

A facile homogeneous precipitationreduction reaction method, which involves PdCl2???PdO?.?H2O???Pd0 reaction path, is used to synthesize the multi-walled carbon nanotubes (MWCNTs) supported Pd nanoparticles (Pd/MWCNTs) catalysts. The particle size of Pd/MWCNTs catalysts can be easily tuned by controlling the hydrolysis temperature of PdCl2. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements show the particle size of Pd/MWCNTs catalysts increases with hydrolysis temperature of PdCl2, which is ascribed to the fact that the particle size of PdO?.?H2O nanoparticles increases with hydrolysis temperature of PdCl2. At the lower hydrolysis temperature, the as-prepared Pd/MWCNTs catalyst possesses the higher dispersion and the smaller particle size. Consequently, the resultant Pd/MWCNTs catalyst exhibits the big electrochemical active surface area and the excellent electrocatalytic performance for hydrazine electrooxidation in strong acidic solutions. In addition, the electrochemical measurement indicate that particle size effect of Pd-NPs occurs during the N2H4 electrooxidation. In brief, the mass activity and specific activity of the Pd/MWCNTs catalyst increases and decreases with decreasing the particle size of Pd-NPs for the N2H4 electrooxidation, respectively.