Obtaining Carbon Nanotubes from CH4 using supported Ni-based catalystsThis work aims to develop nickel catalysts supported on magnesium aluminate substituted with Fe or Mn, using chitosan as chelating agent. For this, the materials were synthesized via microwave-assisted combustion, partially replacing the spinel B site with Fe or Mn, and the impregnation of the active phase was due to incipient moisture. The supports were submitted to X-ray diffraction analysis in order to identify the formed phases and had their specific area determined by BET and the pore distribution calculated by the BJH method. The catalysts were characterized by XRD, infrared spectroscopy (FTIR), field emission scanning electron microscopy (FEG-SEM) and temperature programmed reduction (RTP). From the cracking of methane, the synthesis of carbon nanotubes was carried out, which were evaluated by Raman. In XRD, the 2θ peaks at 36.8, 44.8 and 65.8ºC and in FTIR, the bands at 472 and 682 cm-1 confirm the formation of MgAl2O4. The peaks at 44 and 63º in the XRD were attributed to NiO, indicating that the active phase impregnation occurred. Specific area analysis showed that the supports had a surface area between 16-39 m2/g and a maximum pore volume of 0.06 cm3/g. The SEM-FEG demonstrated that the morphology of the catalysts is modified depending on the doping used. The EDS demonstrated a good dispersion of NiO on the surface of the catalysts. The RTP allowed to evaluate the reduction profile of the catalysts in which strong O Ni/support interactions were observed for Ni/MAQ, Ni/MAF01Q and Ni/MAF05Q samples. Reduction events in the range of 250-500°C were attributed to NiO reduction. Raman confirmed the obtainment of carbon nanotubes.