Ni-SBA-15 Catalysts for Production of Hydrogen and Carbon Nanotubes

Abstract

Thermo Catalytic Decomposition of Methane Using Ni/SBA-15 catalyst was tested in a fixed bed reactor to simultaneously produce hydrogen and carbon nanotubes. SBA-15 nano catalysts were successfully been synthesized using p123, tetraethyl orthosilicate and Ni(NO3)2.6H2O as template, silica source and Nickel nano particle precursors respectively under acidic hydrothermal conditions. The BET surface area, pore size distribution and low angle X-ray Diffraction (XRD) studies revealed that the retention of hexagonally ordered behavior in the catalysts. Wide angle XRD study divulged the crystalline behavior of Nickel oxide species and these Nickel oxide species are in nano range. The catalytic activity experiments were preceded by blank tests intended to ascertain that the reaction did not take place to an appreciable extent in the absence of the catalyst. With SBA-15 alone and Ni alone reaction has not been taken place. Even with 50Ni-SBA-15 and 70Ni-SBA-15 catalysts reaction was not occurred. Only low loading Ni-SBA-15 catalyst was found to be active towards the conversion of methane into the corresponding hydrogen. Among all other catalysts, 30Ni-SBA-15 we observed to produce high yield of hydrogen produced 20% to 50% of H2 at a moderate temperature of 1123K (850°C) and the catalytic activity of the catalyst remains stable for 5hrs. Carbon nanotubes were formed, due to the weak interaction between the metallic nickel and the support. Most of the nickel particles are located on the tip of the produced carbon nanotubes, which avoids rapid deactivation of the catalyst resulted from carbon encapsulation.