Effect of Precursor Status on the Transition from Complex to Carbon Shell in a Platinum Core–Carbon Shell Catalyst

Encapsulating platinum nanoparticles with a carbon shell can increase the stability of core platinum nanoparticles by preventing their dissolution and agglomeration. In this study, the synthesis mechanism of a platinum core–carbon shell catalyst via thermal reduction of a platinum–aniline complex was investigated to determine how the carbon shell forms and identify the key factor determining the properties of the Pt core–carbon shell catalyst. Three catalysts originating from the complexes with different platinum to carbon precursor ratios were synthesized through pyrolysis. Their structural characteristics were examined using various analysis techniques, and their electrochemical activity and stability were evaluated through half-cell and unit-cell tests. The relationship between the nitrogen to platinum ratio and structural characteristics was revealed, and the effects on the electrochemical activity and stability were discussed. The ratio of the carbon precursor to platinum was the decisive factor determining the properties of the platinum core–carbon shell catalyst.