•H2 was produced by catalytic gasification of biomass in presence of Ni/CeO2/Al2O3 catalysts.•Ni/Al2O3 catalyst is more effective for enhancing the H2 yield and tar cracking.•Higher temperatures were significantly resulted in tar cracking and hydrogen production.•An increase in residence time was caused a considerable decrease in the tar yield. Air-steam gasification of wood residue was explored in a research scale fluidized bed. Catalytic activity of two different kinds of metal catalysts (Ni/CeO2/Al2O3) with various catalyst loadings (20, 30, and 40%) was also investigated at various residence time (20, 40, and 60min) and gasification temperature (750, 825, and 900°C). Non-catalytic experiments were also carried out to determine the optimum conditions for tar cracking and hydrogen/syngas production. Results were revealed that the high temperature (∼900°C) and high catalyst loading (∼40%) are favorable for tar cracking and high-purity hydrogen production. It was also found that for a residence time of 60min, the tar cracking at the presence of Ni/CeO2/Al2O3 is 196% more than that of the case without any catalyst, while at the presence of Ni/Al2O3 it drops to 162%. Finally, the experiments were showed that Ni/CeO2/Al2O3 is more suitable for biomass conversion and hydrogen production than Ni/Al2O3.