Low Pt-Doped Crystalline/Amorphous Heterophase Pd12P3.2 Nanowires as Efficient Catalysts for Methanol Oxidation.

Abstract

Pd-based catalysts are attractive anodic electrocatalysts for direct methanol fuel cells owing to their low cost and natural abundance. However, they suffer from sluggish reaction kinetic and insufficient electroactivity in methanol oxidation reaction (MOR). In this work, we developed a facile one-pot approach to fabricate low Pt-doped Pd12P3.2 nanowires with crystalline/amorphous heterophase (termed Pt-Pd12P3.2 NWs) for MOR. The unique crystalline/amorphous heterophase structures promote the catalytic activity by the plentiful active sites at the phase boundaries and/or interfaces and the synergistic effect between different phases. Moreover, the incorporation of trace Pt into Pd lattices modifies the electronic structure and improves the electron transfer ability. Therefore, the obtained Pt-Pd12P3.2 NWs display significantly enhanced electrocatalytic performance toward MOR with the mass activity of 2.35 A mgPd+Pt-1, which is 9.0, 2.9, and 2.0 times higher than those of the commercial Pd/C (0.26 A mgPd-1), Pd12P3.2 NWs (0.82 A mgPd-1), and commercial Pt/C (1.19 A mgPt-1). The high mass activity enables the Pt-Pd12P3.2 NWs to be the promising Pd-based catalysts for MOR.