In this study, H-2 production via low-temperature catalytic steam gasification (CSG) of Athabasca visbroken vacuum residue adsorbed onto NiO-kaolin-based catalysts in a fixed-bed reactor was investigated. The CSG was carried out at 600, 650, and 700 degrees C. Two NiO-kaolin-based catalysts were used, containing either K2O or Cs2O along with BaO. XRD data showed the presence of a crystalline Ni3S2 phase in the spent catalyst only when K was used instead of Cs in the catalyst preparation. CSG experiments conducted for 100 h followed by regeneration confirmed that both catalysts are good candidates for H-2 production via CSG of adsorbed heavy hydrocarbon feed in a fixed-bed reactor unit. However, the H-2/CO2 ratio obtained during CSG is closer to 2 at all three temperatures studied for the 3NiO6K6Ba catalyst. Furthermore, the activation energies determined for the 3NiO6K6Ba and 3NiO6Cs6Ba catalysts for CSG of visbroken residue were 83 and 95 kJ/mol, respectively.