Hydrogen production via methane decomposition over Al2O3-TiO2 binary oxides supported Ni catalysts: Effect of Ti content on the catalytic efficiency

Alumina-titania binary oxides with different TiO2 contents (15%, 25% and 50%) have been prepared via ammonia gas diffusion method. These oxides were applied as supports for 60 wt% Ni which was also precipitated by the same method and tested for methane thermal decomposition to COx- free hydrogen production. Different analytical techniques such as XRD, BET, TPR, Raman spectra, TGA and TEM were performed for characterization the catalysts before and after the catalytic runs. Incorporation of TiO2 in the catalysts facilitates the reduction of the catalysts due to the low formation of NiAl2O4 spinel structure. The Ni/TiO2(25%)- Al2O3 exhibited better activity and stability for catalytic decomposition of methane where about 59% hydrogen yield is obtained at 390 min. TEM images showed that the catalysts produced different types of carbon nanostructured materials such as carbon nanofiber, graphene nanosheets and carbon nanotubes depending on the concentration of TiO2 in the catalysts. (C) 2014 Elsevier Ltd. All rights reserved.