Effect of Mo/Ce ratio in Mo-Ce-Al catalysts on the hydrogen production by steam reforming of glycerol

Alumina-supported molybdena-ceria catalysts were prepared by a sol-gel method and characterized by X-ray diffraction, N₂ sorptometry, UV-vis-NIR diffuse reflectance spectroscopy, SEM and TEM. The effect of the Mo/Ce ratio, reaction temperature, steam to glycerol molar ratio, space velocity and the stability of the catalysts during the reaction were investigated. The results show that the presence of ceria enhances both the activity and the selectivity toward hydrogen. The best reaction temperature was found to be 500 °C for all catalysts, at which the highest hydrogen selectivity of almost 60% was obtained for an optimal cerium loading of 7 wt%; higher ceria loading reduced the capacity to convert glycerol to hydrogen.