A facile approach for preparation of highly dispersed platinum-copper/carbon nanocatalyst toward formic acid electro-oxidation

Abstract

Gaining control over the size and dispersion of binary metal nanoparticles is critical in order to manipulate their catalytic properties. In this study, we demonstrate a facile and effective solid phase evolution approach to prepare a highly dispersed PtCu/C catalyst via a surface substitution and etching separation process with the Pt-decorated Cu particles on carbon as the precursors. It is demonstrated that the dispersion of metal nanoparticles in PtCu/C derived from the present solid phase evolution is better than that in PtCu/C (C) prepared from the co-reduction by NaBH4. As a result, the synthesized PtCu/C shows a larger electrochemically active surface area (ECSA) (48.6m2g−1), higher mass (0.52mAμg−1) and area activities (1.07mAcm−2) than that of the PtCu/C (C) (37.9m2g−1, 0.34mAμg−1 and 0.89mAcm−2, respectively). As compared to commercial Pt/C catalyst, PtCu/C exhibits ca. 2.5 times higher formic acid oxidation (FAO) activities (0.52mAμg−1 and 1.07mAcm−2). The tolerance toward CO poisoning is characterized by CO stripping, the result indicates that both onset (0.43V) and peak (0.50V) potentials of PtCu/C for CO oxidation show a negative shift of ca. 70mV. More significantly, PtCu/C shows high stability in the acid solution, which can maintain 90.1% retention in ECSA after 1000CV cycles. In addition, the solid separation method offers ease of manipulation, allowing the synthesis of a novel class of highly dispersed binary metal nanoparticles.