Screening of metal oxide catalysts for carbon nanotubes and hydrogen production via catalytic decomposition of methane

Abstract

A number of catalysts prepared from transition metals such as copper (Cu), iron (Fe), nickel (Ni), cobalt (Co) and manganese (Mn) on TiO 2 support were tested for the decomposition of methane into hydrogen and carbon. These catalysts were used in the experiments without any pretreatment. The experimental results show that the activities of the metal-TiO 2 catalysts decreased in the order of NiO/TiO 2 > CoO/TiO 2 > MnO x /TiO 2 ≃ FeO/TiO 2 ≃ CuO/TiO 2 . NiO/TiO 2 catalyst exhibited extremely high initial activity in the decomposition of methane. The optimum NiO doping on TiO 2 for the decomposition of methane were obtained at 20mol% NiO. The effective promoters for the catalyst was investigated using 15mol%M/20mol%NiO/Ti02 catalysts (where M = MnO x , FeO, CoO and CuO). 15mol%MnO x /20mol%NiO/TiO 2 was found to be an effective bimetallic catalyst for the catalytic decomposition of methane into hydrogen and carbon, giving higher catalytic activity, attractive carbon nanotube formed as well as longer catalytic lifetime.