Synthesis of PtCu nanowires in nonaqueous solvent with enhanced activity and stability for oxygen reduction reaction Bing Chen a , Daojian Cheng a, * , Jiqin Zhu b, * a State Key Laboratory of OrganiceInorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China b State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing, China highlights  Cu@CuPt core@shell nanowires were synthesized in organic solvent medium.  PtCu nanowires exhibit superior catalytic activity toward the oxygen reduction reaction.  PtCu nanowires show much better durability than the commercial Pt/C catalyst.  Theoretical studies are used to understand the mechanism of enhanced ORR activity. article info Article history: Received 24 April 2014 Received in revised form 19 May 2014 Accepted 20 May 2014 Available online 7 June 2014 Keywords: Platinumecopper nanowire Coreeshell nanostructure Oxygen reduction reaction Fuel cell catalyst abstract Pt-based coreeshell electrocatalysts with one-dimensional (1D) nanostructure show a great opportunity to improve the catalytic activity and durability of pure Pt catalyst for oxygen reduction reaction (ORR). Here, we synthesize Cu@CuPt core@shell nanowires (NWs) with 1D nanostructure by using Cu NWs as templates in organic solvent medium. The ORR mass activity and specific activity of PtCu NWs are 0.216 A mg pt 1 and 0.404 mA cm 2 at 0.9 V, respectively, which are 3.1 and 3.7 times larger than that of the commercial Pt/C catalyst (0.07 A mg pt 1 and 0.110 mA cm 2 , respectively). Theoretical studies suggest that the electronic effect of the Cu substrate on the Pt monolayer could be the main reason for the higher activity of PtCu NWs than that of the commercial Pt/C catalyst. In addition, the PtCu NWs show much better durability than the commercial Pt/C catalyst after stability test. It is expected that the as-synthesized PtCu NWs in organic solvent medium could be excellent candidates as high performance catalysts for ORR. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Proton exchange membrane fuel cells (PEMFCs) are considered to be a promising energy conversion device for the future energy application [1,2]. As is well known, the platinum materials have been regarded as the most effective cathode electrocatalysts for the oxygen reduction reaction (ORR) in PEMFCs [3,4]. However, the high cost, the kinetic limitation of ORR at the cathode, and the durability issues are the main barriers for the commercial appli- cations of pure Pt catalysts [5e7]. Therefore, most investigations have focused on Pt-based bimetallic catalysts such as coreeshell nanomaterials or alloying Pt with less expensive early transition metals [8e10], including Fe [11,12], Co [13,14], Ni [15,16], and Cu [17,18], in order to develop more active and durable catalysts that are superior to the commercial carbon-supported platinum (Pt/C) catalyst. Clearly, when a thin shell of Pt or Pt alloy is deposited on the non-Pt core as a Pt-based coreeshell structure, both its activity and durability are greatly enhanced [19e21]. In addition, when Pt- based catalysts are prepared in one-dimensional (1D) nano- structure with a controlled shape and a high platinum surface area, they can be highly efficient electrocatalyst for the ORR [22,23]. Moreover, these catalysts with 1D nanostructure would demon- strate better durability than the commercial Pt/C catalyst due to the large surface contact and strong adherence between these products and carbon support [22e24]. In general, Pt-based coreeshell electrocatalysts with 1D nano- structure are synthesized by using inexpensive templates, and the size and morphology of the final product can be mainly determined by using templates with different sizes and shapes [25,26]. Cu has been regarded as an important template to synthesize Pt-based coreeshell electrocatalysts with 1D nanostructure, due to its low * Corresponding authors. E-mail addresses: chengdj@mail.buct.edu.cn (D. Cheng), zhujq@mail.buct.edu.cn (J. Zhu). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2014.05.104 0378-7753/© 2014 Elsevier B.V. All rights reserved. Journal of Power Sources 267 (2014) 380e387