Three Ni-based catalysts, namely Ni/ZrO(2)/Al(2)O(3), Ni/La Ca/Al(2)O(3) and Ni(0.5)Mg(2.5)AlO(9) catalysts were prepared, tested and characterized for steam reforming of methane (SRM), especially at high space velocities. Experimental results demonstrated that Ni(0.5)Mg(2.5)AlO(9) catalysts showed excellent catalytic activity, e.g., the high reaction performance (i.e., activity and stability) at a very short residence time of 20 ms. For the accompanied water gas shift (wGS) reaction with the SRM at the steam to methane ratio of 3:1, the overall hydrogen yield depended on both the CH(4) conversion and the CO(2) selectivity. The results showed that CO(2) selectivity had opposite trend compared with CH(4) conversion in such a short-contact process. Catalyst characterizations by XRD, SEM-EDS, TEM and TGA suggested that the good performance of nickel catalysts was closely related with the good dispersion of the active component. The nano-sized nickel particles in strong interaction with the supports would lead to the good dispersion, thereafter having a slight tendency to sintering, and then to coking. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.