Gasification and partial oxidation of 0.25 molar glucose solution was conducted over different metallic nickel (Ni) loadings (7.5, 11, and 18 wt%) on different catalyst supports (theta-Al(2)O(3) and gamma-Al(2)O(3)) in supercritical water. Experiments were carried out at three different temperatures (T) of 400, 450, and 500 degrees C at constant pressure of 28 MPa and a 30 min reaction time (t). For comparison, some experiments were conducted using high loading commercial catalyst (65 wt% Ni on Silica-alumina). Hydrogen peroxide (H(2)O(2)) was used as a source of oxygen in the partial oxidation experiments. Oxygen to carbon molar ratios (MR) of 0.5-0.9 were examined to increase the hydrogen production via carbon monoxide (CO) production. Results showed that in the absence of the catalyst, the optimum molar ratio was 0.8 i.e. 80% of the amount of oxygen required for complete oxidation of glucose. At a molar ratio of 0.8, the hydrogen yield was 0.3 mol/mol, as compared to 0.2 mol/mol glucose at molar ratio of 0.5 and 0.9. This optimized oxygen dose was adopted as a base line for catalysts evaluation. The main gaseous products were carbon dioxide (CO(2)), carbon monoxide (CO), hydrogen (H(2)), and methane (CH(4)). Results also showed that the presence of Ni increased the total gas yield increased in the 7.5-18 wt Ni/Al(2)O(3) catalyst. An increase in MR from 0.55 to 0.8 increased the of carbon dioxide and hydrogen yields from 1.8 to 3.8 mol/mol glucose and from 0.9 to 1.1 mol/mol. The carbon monoxide and methane yields remain constant at 2 and 0.5 mol/mol glucose, respectively. The introduction of hydrogen peroxide (H(2)O(2)) prior to the feed injection inhibited the catalyst activity and did not increase the hydrogen yield whereas the introduction of H(2)O(2) after 15 mm of reaction time increased the hydrogen yield from 0.62 mol/mol to 1.5 mol/mol. This study showed that approximately the same hydrogen yield can be obtained from the synthesized low nickel alumina loading (18 wt%) catalyst as with the 65 wt% nickel on silica-alumina loading commercial catalyst. The highest H(2) yield of 1.5 mol/mol glucose was obtained with commercial Ni/silica-alumina with a BET surface area of 190 m(2)/g compared to 1.2 mol/mol with the synthesized Ni/theta alumina with a BET surface area of 46 m(2)/g. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.