Abstract
The oxygen reduction reaction is the limiting half-reaction in hydrogen fuel cells. While Pt is the most active single component electrocatalyst for the reaction, it is hampered by high cost and low reaction rates. Most research to overcome these limitations has focused on Pt/3d alloys, which offer higher rates and lower cost. Herein, we have synthesized, characterized, and tested alloy materials belonging to a multilayer family of electrocatalysts. The multilayer alloy materials contain an AuCu alloy core of precise composition, surrounded by Au layers and covered by a catalytically active Pt surface layer. Their performance relative to that of the commercial Pt standards reaches up to 4 times improved area-specific activity. Characterization studies support the hypothesis that the activity improvement originates from a combination of Au-Pt ligand effects and local strain effects manipulated through the AuCu alloy core. The presented approach to control the strain and ligand effects in the synthesis of Pt-based alloys for the ORR is very general and could lead to promising alloy materials. (Graph Presented).
| Original language | English |
|---|---|
| Pages (from-to) | 17-24 |
| Number of pages | 8 |
| Journal | ACS Catalysis |
| Volume | 7 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 6 2017 |
Funding
We acknowledge support from the US DOE Office of Basic Energy Sciences, Division of Chemical Sciences (FG-02-05ER15686). We also acknowledge the University of Michigan X-ray Micro-Analysis Laboratory and Chemistry Technical Services for use of characterization and analytic facilities. Research was also supported as part of a user project by the Oak Ridge National Laboratory (ORNL) Center for Nanophase Materials Sciences, which is an Office of Science User Facility (K.L.M.). Finally, we acknowledge H. Xin and A. Holewinski for helpful discussions and experimental assistance.
Keywords
- core-shell nanoparticles
- electrocatalysis
- fuel cells
- oxygen reduction
- platinum alloy catalysts
