Fig. 5: Theoretical modeling of enhanced stability and activity of the ternary alloy catalyst.

a A comparison of the calculated dissociation energies of Cu atom from pure Cu and PtPdCu alloy based on cluster and slab models. b A free energy (ΔG) diagram comparing the energetics for the different ORR species and the reaction barriers for some key elementary steps in ORR on Pt (111), Pd (111), and PtPdCu (111) surface models at 0.9 V with respect to Computational Hydrogen Electrode (CHE). “TS1–TS3” represents the transition states for the three elementary steps, as indicated. c Illustration of the ORR mechanism based on the corresponding models of Pt (111), Pd (111), and PtPdCu (111) surfaces for the calculation. Red, dark-blue, green, light-blue, and white balls represent Pt, Pd, Cu, O, and H atoms, respectively.