The objective of this study is to develop a novel supported nano-NiO catalysts for tar removal in biomass gasification/pyrolysis, to significantly enhance the quality of the produced gases. For this purpose, the supported nano-NiO/gamma-Al2O3 catalyst was prepared by deposition-precipitation (DP) method. Different analytical approaches such as XRD, BET, TEM and SEM/EDX were used to characterize the synthesized catalysts. The results showed that the prepared nano-NiO/gamma-Al2O3 catalysts had an egg-shell structure with a loading of NiO in catalysts over 12 wt %, and they had also a higher BET ...