In this paper, the results obtained in the methane decomposition reaction promoted by a Ni catalyst supported on MgAl2O4 spinel are presented. The textural properties of the catalyst were investigated by X-ray diffraction (XRD), N-2 adsorption/desorption isotherms (BET and BJH methods), thermogravimetric (TGA) and temperature-programmed reduction (TPR) analysis. The influence of the operating conditions employed on the methane decomposition was studied. According to the results, it was found that a N-2:CH4 molar ratio of 7:1 and catalyst reduction temperature of 700 degrees C/1 h were the best conditions for methane decomposition. In addition, in the methane decomposition over Ni/MgAl2O4, multiwall carbon nanotubes were formed. (C) 2012 Elsevier B.V. All rights reserved.