High-yield hydrogen and methane production via supercritical water gasification of glucose using Ni/Cu-doped CeO2 catalyst: Synthesis process optimization utilizing RSM

•Ni/Cu-doped CeO2 catalyst was fabricated to be used in H2 and CH4 production.•The effects of synthesis conditions on catalyst performance in SCWG was explored.•Cu was determined to exert a beneficial impact on the production of H2 gas.•Maximum H2 yield was obtained to be 5.46 mmol.g-feed-1.•Maximum CH4 yield was obtained to be 2.45 mmol.g-feed-1. This study investigates the synthesis and performance of a nickel/copper-doped cerium oxide catalyst for hydrogen and methane production during the supercritical water gasification of glucose, which is important for producing clean fuel. The effects of key synthesis parameters—cerium molar concentration, nickel salt to cerium salt, and copper salt to cerium salt weight ratios—on catalyst activity were optimized using Response Surface Methodology. The catalyst demonstrated significant improvements in hydrogen and methane yields compared to supercritical water gasification without a catalyst, achieving increases of 181 % and 226 %, respectively. The optimal synthesis conditions yielded 5.46 mmol.g-feed-1 hydrogen and 2.45 mmol.g-feed-1 methane with minimal error between experimental and predicted results. Characterization techniques, including XRD, TEM, and EDS-Mapping, confirmed the catalyst's uniform dopant dispersion. Reusability studies revealed deactivation due to coke deposition, but performance was partially restored via regeneration. This work highlights the potential of aforementioned effective catalyst for clean fuel production. [Display omitted]