We report a strategy to stabilize first row transition metal in Pt-based alloy nanoparticles (NPs) and to enhance their electrocatalysis for oxygen reduction reaction (ORR). Using 8 nm FePt as an example, we demonstrate that Fe can be stabilized more efficiently in a core/shell structured L10-FePt/Pt in which the intermetallic FePt core is covered by a 2~3 atomic layer Pt shell. The presence of Fe in the alloy core induces the desired compression of the thin Pt shell. As a result, the core/shell NPs show much enhanced ORR catalysis not only in 0.1 M HClO4 solution (both at room temperature and 60°C), but also in the membrane electrode assembly (MEA) at 80°C. They have a mass activity of 0.7 A/mgPt in RDE test and show no obvious mass activity loss after 30,000 potential cycles between 0.6 V and 0.95 V in MEA, meeting the DOE 2020 target (&lt;40% loss in mass activity). We are extending the concept and preparing other L10-MPt/Pt NPs with reduced particle size as a highly efficient ORR catalyst for automotive fuel cell applications.

Atomically Thin Pt Coated over Intermetallic FePt Nanoparticles for Efficient Oxygen Reduction Catalysis in Fuel Cells

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.