title: Kinetically controlled autocatalytic chemical process for bulk production of bimetallic core-shell structured nanoparticles.
abstract: Although bimetallic core@shell structured nanoparticles (NPs) are achieving prominence due to their multifunctionalities and exceptional catalytic, magnetic, thermal, and optical properties, the rationale underlying their design remains unclear. Here we report a kinetically controlled autocatalytic chemical process, adaptable for use as a general protocol for the fabrication of bimetallic core@shell structured NPs, in which a sacrificial Cu ultrathin layer is autocatalytically deposited on a dimensionally stable noble-metal core under kinetically controlled conditions, which is then displaced to form an active ultrathin metal-layered shell by redox-transmetalation. Unlike thermodynamically controlled under-potential deposition processes, this general strategy allows for the scaling-up of production of high-quality core-shell structured NPs, without the need for any additional reducing agents and/or electrochemical treatments, some examples being Pd@Pt, Pt@Pd, Ir@Pt, and Ir@Pd. Having immediate and obvious commercial potential, Pd@Pt NPs have been systematically characterized by in situ X-ray absorption, electrochemical-FTIR, transmission electron microscopy, and electrochemical techniques, both during synthesis and subsequently during testing in one particularly important catalytic reaction, namely, the oxygen reduction reaction, which is pivotal in fuel cell operation. It was found that the bimetallic Pd@Pt NPs exhibited a significantly enhanced electrocatalytic activity, with respect to this reaction, in comparison with their monometallic counterparts.
authors: Nanoelectrochemistry Laboratory, Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan, Republic of China.
authors: Fadlilatul
authors: F
authors: Taufany
authors: Chun-Jern
authors: CJ
authors: Pan
authors: John
authors: J
authors: Rick
authors: Hung-Lung
authors: HL
authors: Chou
authors: Mon-Che
authors: MC
authors: Tsai
authors: Bing-Joe
authors: BJ
authors: Hwang
authors: Din-Goa
authors: DG
authors: Liu
authors: Jyh-Fu
authors: JF
authors: Lee
authors: Mau-Tsu
authors: MT
authors: Tang
authors: Yao-Chang
authors: YC
authors: Lee
authors: Ching-Iue
authors: CI
authors: Chen
mesh_terms: D002384:Catalysis; D003460:Crystallization / Q000379:methods; D004595:Electroplating / Q000379:methods*; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010984:Platinum; D010165:Palladium