(204b) A Study of Oxygen Reduction Reaction On Pt Monolayers Electrocatalysts with Core-Shell Structure

The polymer electrolyte membrane fuel cell (PEMFC) is considered a potential power sources for automotive and residential applications. However, high content of Pt as the cathode catalysts and the slow kinetics of oxygen reduction reaction on conventional Pt catalysts is still one major obstacle for its wide-spread commercialization. We recently discovered a new class of electrocatalysts for the ORR based on a Pt monolayer deposited on metal or alloys nanoparticles (1,2), which has shown several times higher Pt mass activity compared to commercial Pt/C. In this presentation, we will show how to deposite the Pt monolayers to carbon supported metal nanoparticles using the galvanic displacement of under-potential deposition of Cu monolayer to produce core-shell materials either on an RDE tip or at gram scales. The scanning transmission electron microscopy (STEM) and extended X-ray absorption fine structure (EXAFS) studies of Pt monolayers deposited onto carbon supported Pd3Co/C nanoparticles for ORR provides more insights into the structure ? activity correlation at atomic scale for this type of core-shell structure electrocatalysts.

(1) Adzic, R. R.; Zhang, J.; Sasaki, K.; Vukmirovic, M. B.; Shao, M. H.; Wang, J. X.; Nilekar, A. U.; Mavrikakis, M.; Valerio, J. A.; Uribe, F. Top. Catal. 2007, 46, 249.

(2) Zhang, J.; Mo, Y.; Vukmirovic, M. B.; Klie, R.; Sasaki, K.; Adzic, R. R. J. Phys. Chem. B 2004, 108, 10955.