Activated charcoal supported nickel-based catalysts such as Ni/AC, Ni-Y/AC, Ni-Fe/AC, and Ni-Co/AC were formulated and their catalytic activity for the gasification of glucose in supercritical water were investigated using a packed-bed reactor at 650 degrees C, 28 MPa. A set of glucose gasification experiments was also carried out without catalyst and with AC to provide baseline data. Loading of small amounts of Y to the Ni/AC catalyst appeared to increase both the extent of gasification and hydrogen yield while loading of Fe or Co metal to the Ni/AC catalyst did not give any positive effect on the gasification results. Effect of catalyst composition, temperature, reactant concentration, and reactor residence time on the glucose gasification with the Ni-Y/AC catalyst was examined. Catalyst analysis indicates that adding of Y into the Ni/AC catalyst inhibited carbon formation to a great extent, thereby maintaining catalytic activity of the Ni metal for H(2) formation reactions. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.