Fuel Cell Electrocatalysis
Alloys of Pt have been shown to improve the kinetics of oxygen reduction. We have found that the deposition of Zn onto Pt creates a substrate upon which we have measured the kinetic parameters for the electrodeposition of Zn under close-to-industrial conditions. We are now studying the chemical nature of the surface alloy using UHV techniques such as Auger Spectroscopy. We have also found that the Pt/Zn alloy modifies the kinetics of the oxygen reduction reaction. Changes in the surface composition (Pt:Zn ratio) during CO oxidation or ORR was also found using Auger spectroscopy. We are also testing modified MEAs in a home built fuel cell test station to study the stability of the Pt/Zn alloy. The stability of the alloy is being studied using electrochemically created alloy nanoparticles on a carbon support. We use AFM to measure the strength of adhesion of these particles to the support.