Fabrication of platinum-cobalt nanowires by centrifugal electrospinning as oxygen reduction catalyst for PEMFC

Investigation for novel catalytic materials is quite important for the development of fuel cell as well as hydrogen economy. In this study, platinum-cobalt (PtCo) bimetallic nanowires are prepared successfully by the centrifugal electrospinning technique and their potential as electrocatalyst is evaluated for proton exchange membrane fuel cell (PEMFC). The influences of operation conditions on nanowire morphology are studied, which include the rotation rate of spinneret, applied electric field, and nanowire composition. The electrochemical performance of the prepared nanowires is studied by performing the tests of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) to characterize the electrochemical active surface area (ECSA) and oxygen reduction reaction (ORR) activity. The accelerated degradation tests (ADT) are also conducted to examine the durability of the nanowires. The membrane electrode assembly (MEA) using PtCo nanowires as cathode electrocatalyst is also made and its performance is compared with conventional MEA using Pt/C catalyst. It is found that under the situation of 1600 rpm of rotation rate, 12 cm of collection distance, and 13 kV of applied voltage, PtCo nanowires can be obtained with excellent morphology and the minimum mean diameter is 76 nm for the case of atomic ratio Pt:Co = 4:1. The corresponding ECSA is 41.2 m2g−1 and the LSV and ADT results show the resultant PtCo nanowires exhibit better ORR activity and durability than Pt/C catalyst.