Changes in electronic states of platinum-cobalt alloy catalyst for polymer electrolyte fuel cells by potential cycling

- The Pt-Co alloy catalyst is more durable than Pt catalyst under potential cycling.
- The XPS spectra of Pt4f shows Pt(OH)2 exists on Pt catalyst in initial MEA.
- Pt(OH)2 of Pt catalyst decreased after potential cycling suggesting Pt dissolution.
- Platinum in Pt-Co alloy catalyst is in metallic state and is stable.
- The XPS spectra of Co 2p suggest that Ptrich layer is thicker than 1.4 nm.