Ce-modified mesoporous zirconia (Zr-Ce-X) supports were prepared by a templating sol-gel method with a variation of Ce/Zr molar ratio (X). 20 wt% Ni catalysts supported on Zr-Ce-X (X=0, 0.1, 0.3, 0.5, 0.7, and 0.9) were then prepared by an incipient wetness impregnation method for use in hydrogen production by auto-thermal reforming of ethanol. The effect of Ce/Zr molar ratio (X) on the catalytic performance of Ni/Zr-Ce-X (X - 0, 0.1, 0.3, 0.5, 0.7, and 0.9) catalysts was investigated. All the Ni/Zr-Ce-x (X = 0, 0.1, 0.3, 0.5, 0.7, and 0.9) catalysts exhibited complete conversion of ethanol at 500 degrees C, while product distributions over the catalysts were different depending on the Ce/Zr molar ratio (X). Hydrogen selectivity over Ni/Zr-Ce-X (X - 0, 0.1, 0.3, 0.5, 0.7, and 0.9) catalysts showed a volcano-shaped curve with respect to Ce/Zr molar ratio (X). Among the catalysts tested, Ni/Zr-Ce-0.7 showed the best catalytic performance in hydrogen production by auto-thermal reforming of ethanol. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved