Synthesis of Pd@Pt3Co/C core–shell structure as catalyst for oxygen reduction reaction in proton exchange membrane fuel cell

Abstract

The proton exchange membrane fuel cell (PEMFC) is a good source of alternative energy because its main product is water. To increase the catalytic activity and durability of the nanoparticles in the oxygen reduction reaction (ORR), catalysts with a novel core–shell structure were synthesized. The core–shell structure is composed of a singular core, Pd, and a binary alloy shell, PtCo, which exhibits high ORR activity. TEM analysis confirms that the core–shell structure of Pd@Pt3Co/C comprises Pt3Co alloy that is deposited on Pd nanoparticles. In testing of the rotating ring-disk electrode, the ORR activity of Pd@Pt3Co/C is better than that of other samples – Pt/C, Pd/C and Pd@Pt/C. The stability test of Pd@Pt3Co/C shows more decay after 20,000 cycles and then recover during the next 10,000 cycles. The PEMFCs using Pt/C, Pd/C, Pd@Pt/C and Pd@Pt3Co/C in the cathodes show the maximum power densities of 639.3, 382.4, 721.8 and 854.0 mW cm−2, respectively, indicating that Pd@Pt3Co/C outperforms the others and is suitable for use in the PEMFC. After the stability test, the maximum power density of Pd@Pt3Co/C shows almost no obviously decay, which confirms Pd@Pt3Co/C can act as the outstanding catalyst. The improved activity of Pd@Pt3Co/C is associated with the high utilization of Pt3Co shell on the Pd core, the ligand effect, the lattice strain effect and the synergic effect between Pd core and Pt3Co alloy shell.