Influence of calcination temperatures of Feitknecht compound precursor on the structure of Ni–Al2O3 catalyst and the corresponding catalytic activity in methane decomposition to hydrogen and carbon nanofibers Original Research Article

XRD, N2 physisorption, TPR, XPS, TEM and in situ thermal balance were employed to investigate the influence of calcination temperatures on the structure of Ni–Al2O3 catalysts prepared from Feitknecht compound precursor. The activity of the Ni–Al2O3 catalysts for methane decomposition to produce hydrogen and carbon nanofibers was investigated. In NiO–Al2O3 samples calcined at 573–873 K, only NiO phases were identified, while sample calcined at 1023 K, showed segregated NiAl2O4 spinel was formed. Both the interaction of NiO with Al2O3 in NiO–Al2O3 and that of Ni with Al2O3 in the corresponding Ni–Al2O3 became more complex with the increase of calcination temperature. It seems that the activity of Ni in Ni–Al2O3 for methane decomposition is dependent on the interaction of Ni with Al2O3 and the content of the corresponding Ni.