Carbon Nanofiber Supported Ni Catalysts for CO Methanation

Carbon nanofiber (CNF) supported Ni catalysts (Ni/CNFs) were prepared for CO methanation. The activity of the catalyst was compared with the Ni catalyst supported by the commonly used gamma-Al2O3(Ni/gamma-Al2O3). In addition, large diameter carbon nanotube (LCNT) supported Ni catalyst (Ni/LCNT) was also compared with the Ni/CNF catalyst. Ni/CNF exhibited a higher activity toward CO methanation than that of the Ni/LCNT and Ni/gamma-Al2O3. According to the XRD and TPR results, it was inferred that the key factor influenced the catalytic activity was the existence of large amount of the delocalized pi-electrons in CNFs. Preparation method had an effect on the catalytic activity of the Ni/CNF catalyst. The catalyst prepared by the deposition precipitation method exhibited a higher dispersion, which led to more available active component interacting with the delocalized pi-electrons. Thus, both the activity and stability of the Ni/CNF catalyst prepared by deposition precipitation method for CO methanation were higher than that of the catalyst prepared by impregnation method.