A Facile Preparation of Palladium Catalysts Supported on Hollow Polypyrrole Nanospheres for Ethanol Oxidation

Graphical abstract: Ppy hollow nanospheres with uniform size have been successfully prepared and employed as the supports for Pd nanoparticles with smaller particle size and better dispersion. Electrochemical measurements demonstrate that the obtained Pd/H-ppy exhibits good electrocatalytic activity and stability for ethanol electrooxidation. - Highlights: • Ppy hollow nanospheres support provides new ways to develop catalyst materials as a result of its distorted structure and large surface area. • Ppy hollow nanospheres with uniform size have been successfully prepared through chemical oxidative polymerization of pyrrole in the presence of PS microspheres. • Pa nanoparticles have been successfully assembled on the surface of hollow ppy nanospheres. • Pd/H-ppy exhibits good electrocatalytic activity and stability for ethanol electrooxidation. - Abstract: A facile and low-cost preparation of Pd nanoparticles on the surface of hollow polypyrrole (ppy) nanospheres was introduced in this paper through solvothermal reaction. Herein, uniform polystyrene (PS) microspheres as sacrificial templates were rapidly prepared through a emulsion polymerization method, and then the hollow ppy nanospheres were obtained through chemical oxidative polymerization of pyrrole in the presence of PS microspheres. According to X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements, the novel Pd nanoparticles are well-dispersed on the surface of hollow ppy nanospheres with a relatively narrow particle size distribution. The diameters of hollow ppy nanospheres range from 240 to 280 nm, and the average shell thickness is about 15 nm. Electrochemical analysis results indicate that the as-prepared Pd nanoparticles on the surface of hollow ppy nanospheres (Pd/H-ppy) exhibit good electrocatalytic activity and stability for ethanol electrooxidation