A Study of the Effect of PVP As Stabilizing Agent In Platinum Nanoparticle Synthesis and the Implications towards Oxygen Reduction Reaction

The stability of precious metals under acidic conditions is a potential challenge for several applications including proton exchange membrane fuel cells (PEMFCs). Strategies addressing this challenge have been tested including the addition of organic stabilizing agents such as polypyrrole. Organic stabilizing agents have also been used to synthesize precious metal nanoparticles by assisting in the regulation of the nucleation and growth rates. In this study, well-defined 3 nm Pt nanoparticles were synthesized using a combination of metal precursor, Hexachloroplatinic acid (H₂PtCl₆), surfactant (PVP), alcohol (methanol), and water. The stability of these nanoparticles was evaluated under acidic conditions. Washed (in cycles of ethanol and hexane) and unwashed batches of Pt nanoparticles were characterized using a transmission electron microscope. Further studies to determine the electrocatalytic properties of the particles were performed using cyclic voltammetry. These results were complimented with temperature-programmed experiments after supporting the nanoparticles on silica. A detailed analysis and discussion of these results is made in this presentation.