Display omitted •Clean hydrogen gas production by the catalytic decomposition of methane.•Highly selective monometallic catalysts for methane decomposition.•Facile incorporation of plentiful elements on the Santa Barbara Amorphous-15.•Nickel oxide over Santa Barbara Amorphous-15 converted 40% of methane at 700 °C. In this work, we synthesized monometallic catalysts based on Ni, Cu, Co, Mn, Fe, Zn, and W supported on Mesoporous Santa Barbara Amorphous-15 (SBA-15) to produce hydrogen and carbon nanomaterials through catalytic methane decomposition (CMD). Highly dispersed metal oxides supported on the SBA-15 surface promotes the formation of either carbon nanotubes or carbon nanofibers after CMD. Furthermore, the catalytic activity results showed the Ni/SBA-15 catalyst performed the highest methane conversion (40%) as well as it displayed superior stability during 13 h at 500 °C (23% of conversion). The resulting nanoparticle oxides, except for the Zn sample that presented a high dispersion throughout the SBA-15.