Carbon Nanotubes Supported Nickel as the Highly Efficient Catalyst for Hydrogen Production through Glycerol Steam Reforming

Different amounts of nickel were loaded on carbon nanotubes (CNTs) by an impregnation method and characterized by N2 adsorption/desorption isotherms, X-ray diffraction, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, H2 chemisorption, and transmission electron microscopy to study the porosity, the crystalline phases, the surface property, the reducibility property, the metallic Ni dispersion, and morphology. It was found that two types of Ni2+ species differing by the interaction with the CNTs support coexisted; the amount of free NiO was dominated by Ni content. More metallic Ni species could be thus obtained on the catalyst with higher Ni loading. Furthermore, the descriptor between the active phases property and the catalytic performances was established, which suggested that both the surface area and the state of Ni dispersion synergistically determined the catalytic reaction. The catalysts showed the good catalytic performances at a relative lower reaction temperature of 375 °C.