Hydrogen selectivity and carbon behavior during gasoline steam reforming over nano-Al2O3 catalysts

In this work, the influence of metal type (Ni and Co) and preparation method (co-precipitation and impregnation) on catalytic gasoline steam reforming (CGSR) using nano-Al2O3 support were studied at different reaction temperature (500-800 degrees C). The structure and surface properties of fresh and spent catalysts were tested by different characterization tools such as TGA, TPR, XRD, HRTEM, BET surface areas and Raman spectroscopy. Results show that product distribution is dependent on both preparation method and metal type. Co/Al2O3 is the most selective catalyst for hydrogen production from GSR reaction; H-2 selectivity reached 70 % over this catalyst at 800 degrees C. While, when considering hydrogen production and carbon deposition in the meantime, Ni/Al2O3 is the best one because of the generation of non-deactivating carbon on its surface. CO conversion represented as CO2/(CO + CO2) is an indication of the WGS reaction, over all of the prepared catalysts, WGS reaction was preferred at low temperature. On the other hand, we can show that Ni catalysts favor WGS reaction more than that of co catalyst. Moreover, a higher thermal stability and graphitization degree of deposit carbon were obtained on Ni-Al2O3 and Co/Al2O3.