Synthesis of Ni and Ni–Cu supported on carbon nanotubes for hydrogen and carbon production by catalytic decomposition of methane

Abstract

Nickel and nickel–copper alloy supported on carbon nanotubes (CNTs) were examined as catalysts for hydrogen production by methane decomposition. The Ni/CNT and Ni–Cu/CNT catalysts were characterized using field emission scanning electron microscopy, energy dispersive X-ray microscopy, transmission electron microscopy and X-ray diffraction. The performance of the catalysts was dependent on the catalyst composition and reaction temperature. The Ni78Cu22/CNT catalyst exhibited the excellent catalytic performance with a stable methane conversion of 0.8 at 700°C, a carbon yield rate of 0.08gC/(mingNi) at 743°C and a carbon yield of 602gC/gNi at 700°C. Carbon materials with various morphologies, i.e., herringbone carbon nanofibers (CNFs), platelet CNFs, bamboo-shaped CNFs, branched CNFs, multi-branched CNFs and onion-like carbons, depending on the catalyst composition and reaction temperature, were obtained. The morphology of the produced carbon material was correlated with the growth mechanism of the carbon material on the catalyst.