Enhanced electrocatalytic performance of Pt monolayer on nanoporous PdCu alloy for oxygen reduction

► Pt monolayer-covered nanoporous PdCu catalysts are prepared by a Cu-underpotential deposition-Pt displacement strategy. ► Compared with Pt/C catalyst, the Pt monolayer-modified nanoporous PdCu show much enhanced activity and stability for oxygen reduction reaction (ORR). ► Pt monolayer on PdCu alloy core with a Pd:Cu ratio of 1 shows the highest activity for ORR.