Characterization of the Platinum-Carbon Interface for Electrochemical Applications

Fuel cell catalysts suffer stability issues that are related to reaction-induced corrosion, catalyst sintering, and detachment. In the case of carbon-supported platinum nanoparticles, the stability can be improved by changing the carbon structure and tuning the metal support interaction. The large structural and chemical variability of carbon offers a potential for improved electrochemical properties. However, a rational design of the metal carbon interface requires knowledge about the relation between the carbon structure and the resulting platinum carbon interaction. Using a variety of complementary analytical methods such as atomic scale imaging and local as well as integral spectroscopic tools in combination with different electrochemical aging protocols, we elaborate a relation between the structure-determined surface properties of the carbon and the resulting platinum carbon interface. Atomic-scale imaging of the interface combined with electron spectroscopic methods enables distinction between different interaction types and associated bonding state and charge transfer properties. For the investigations, three differently structured industrial carbon support structures have been selected. The reported findings define solid criteria for a rational design of improved carbon supports.