Synthesis of mesoporous hollow polypyrrole spheres and the utilization as supports of high loading of Pt nanoparticles

In this paper, mesoporous hollow polypyrrole spheres (MHPS) are prepared via a chemical polymerization from pyrrole using silica spheres as hard templates. The MHPS possesses a hierarchical structure with hollow macroporous core in combination with mesoporous shell and a high surface area (117.5 m2 g−1) and pore volume (0.34 cm3 g−1). And this material is applied to support Pt nanoparticles to form Pt/MHPS catalyst via a simple chemical reduction method by using formic acid as reducing agent for methanol oxidation reaction (MOR). In the Pt/MHPS, the Pt nanoparticles in mean diameter of ∼3.6 nm are uniformly dispersed on the shells of the hollow polypyrrole spheres. The resulting Pt/MHPS shows a higher specific electrochemically active surface area (ECSA), improved activity and poisoning tolerance for MOR compared with the carbon black (Vulcan XC-72R)-supported Pt catalyst.