A series of nickel-copper nanoparticles were synthesized using the polyol reduction method and examined as catalysts for hydrogen production by methane decomposition. The effects of surfactant polyvinylpyrrolidone (PVP), carbon nanotube (CNT) support and heterogeneous nucleation seed, i.e., H2PtCl4 solution on the structural and catalytic properties of the resulting catalysts were studied. The catalysts were extensively characterized using field scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and N-2 adsorption-desorption tests. The catalytic performance of the catalysts was evaluated in terms of methane conversion and carbon yield. It was found that the Ni-Cu alloying degree in the catalyst was critical to achieve high activity and that the catalytic performance was also closely related to the CNT support, the size and dispersion of the Ni-Cu particles. Among the catalysts, the Ni-Cu/CNT catalyst synthesized in the presence of PVP and H2PtCl4 solution exhibits the best catalytic activity with a stable methane conversion value of 0.8 and a carbon yield of 616 g C g(Ni)(-1) at 700 degrees C. The structures of the produced carbon materials were also characterized. Filamentous carbon nanofibers were obtained from the catalysts with high Ni-Cu alloying degrees while limited carbon lumps were generated from the catalyst with a low Ni-Cu alloying degree. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.