Controlled Synthesis of Pd–Pt Alloy Hollow Nanostructures with Enhanced Catalytic Activities for Oxygen Reduction

• Published in: ACS nano 2012-03, Vol.6 (3), p.2410-2419
• Main Authors: Hong, Jong Wook, Kang, Shin Wook, Choi, Bu-Seo, Kim, Dongheun, Lee, Sang Bok, Han, Sang Woo
• Format: Article
• Language: English
• Subjects: Alloys - chemistry; Catalysis; Catalysts; Dendritic structure; Electrochemistry; Morphology; Nanostructure; Nanostructures - chemistry; Nanotechnology - methods; Oxidation-Reduction; Oxygen - chemistry; Palladium; Palladium - chemistry; Palladium base alloys; Platinum; Platinum - chemistry; Reduction; Strategy; Water - chemistry
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn2046828

Pd–Pt alloy nanocrystals (NCs) with hollow structures such as nanocages with porous walls and dendritic hollow structures and Pd@Pt core–shell dendritic NCs could be selectively synthesized by a galvanic replacement method with uniform Pd octahedral and cubic NCs as sacrificial templates. Fine control over the degree of galvanic replacement of Pd with Pt allowed the production of Pd–Pt NCs with distinctly different morphologies. The synthesized hollow NCs exhibited considerably enhanced oxygen reduction activities compared to those of Pd@Pt core–shell NCs and a commercial Pt/C catalyst, and their electrocatalytic activities were highly dependent on their morphologies. The Pd–Pt nanocages prepared from octahedral Pd NC templates exhibited the largest improvement in catalytic performance. We expect that the present work will provide a promising strategy for the development of efficient oxygen reduction electrocatalysts and can also be extended to the preparation of other hybrid or hetero-nanostructures with desirable morphologies and functions.