Brenna Gibbons1 Melissa Wette1 Drew Higgins1 Apurva Mehta2 Ryan Davis2 Thomas Jaramillo1 Bruce Clemens1

1, Stanford Univ, Stanford, California, United States
2, SLAC National Accelerator Laboratory, Menlo Park, California, United States

The oxygen reduction reaction (ORR) is a critical reaction in energy technologies such as fuel cells and metal-air batteries. While Pt-based catalysts are the conventional choice for acidic electrolytes, favorable oxygen reduction kinetics and stability considerations that occur in alkaline electrolytes provide possibility for using non-platinum group metal catalysts, including silver. In particular, bimetallic or alloyed systems of silver and copper have been predicted by theory to be active for the ORR [1]. Recently, we have shown that co-sputtering silver and copper as both thin films and nanoparticles results in ORR catalytic activity that surpasses that of either metal on its own [2]. In order to investigate the mechanism of this improvement, we developed several operando electrochemical cells for use at the Stanford Synchrotron Radiation Lab. In this work we investigate these bimetallic catalysts using in situ x-ray absorption spectroscopy (XAS) and x-ray diffraction (XRD) in order to help understand the activity enhancements seen when combining copper and silver for the ORR.

1. K. Shin, D.H. Kim, and H.M. Lee. ChemSusChem (2013), 6: 1044-1049.
2. Higgins et al., in preparation.