Abstract:

Carbon supported palladium (Pd) nanoparticles were used as a model core material for the synthesis of platinum (Pt) monolayer core-shell catalysts using rotating disk electrode method and a copper (Cu) under potential deposition technique. The impact of Nafion on the synthesis process was revealed by electrochemical testing with various Nafion contents. The existence of Nafion influenced the Cu under potential deposition, galvanic replacement and eventually the oxygen reduction reaction activity of the core-shell catalyst. However, as long as the Nafion content was less than 5 wt% in the test film, adding Nafion could help to bind catalyst onto the surface of electrode while maintaining promising catalytic activity. Unique anion adsorption/desorption peaks were observed on the surface of Pd in H₂SO₄ solution, which turned out to be a useful indicator to evaluate the impact of Nafion on the synthesis of the core-shell catalysts.

Key words: core-shell catalyst, oxygen reduction reaction, , copper under potential deposition, Nafion content, anions adsorption