Synthesis of Pt and bimetallic PtPd nanostructures on Au nanoparticles for use as methanol tolerant oxygen reduction reaction catalysts
Abstract
Core–shell structured Au–PtPd/C and Au–Pt/C nanoparticles (NPs) were prepared using a successive reduction process on carbon supported Au with PtPd and Pt particles. Structural analyses of the core–shell NPs revealed uniformly distributed fine particles (<5 nm in diameter) on carbon particles and selectively deposited Pt and bimetallic PtPd structures on the Au surface. The activity of the NPs was investigated for the oxygen reduction reaction (ORR) in both H2SO4 solutions with and without CH3OH. In Au–Pt and Au–PtPd NPs, the activities for the ORR decreased in the solution without CH3OH as the amount of Pd increased; moreover, Au–PtPd NPs showed higher activity than Au–Pt NPs in solution with CH3OH due to its enhanced tolerance for methanol oxidation. Thus, the high methanol oxidation reaction tolerance of Au–PtPd NPs is ascribed to the synergistic effect resulting from its thin structure and bimetallic PtPd composition.