Hydrogen production through diesel steam reforming over rare-earth promoted Ni/γ-Al2O3 catalysts

Rare-earth (La, Ce, Yb) promoted Ni/gamma-Al2O3 catalysts were prepared by impregnation method. Activity and carbon formation resistance of the prepared catalysts were evaluated under various reaction conditions. Catalyst characterizations with TG, TPR and H-2 chemisorption were carried out to investigate the promoting mechanism. Experimental results show that rare-earth promoters, especially Yb promoter, obviously improve the activity and carbon formation resistance of Ni/gamma-Al2O3 catalyst, and Yb-Ni catalyst shows even higher performance than several commercial catalysts. According to the characterization results, Yb promoter enhances the interaction between the active metal and support, thus increasing the active metal's dispersion and improving its performance. Furthermore, the obvious difference in diesel conversion between Yb-Ni catalyst and others was shown in the temperature range of 450-550 degrees C, which would be the reason for its excellent carbon resistance.