Fly ash (FA), an industrial waste material, has been treated by physical and chemical methods. These materials were then employed as supports for preparation of Ru-based catalysts for H-2 generation from ammonia decomposition. The physicochemical properties of the supports and Ru-based catalysts were characterised using several techniques. The results revealed that the surface area of FA could be enhanced and thus improved the dispersion of Ru particles, resulting in higher catalytic activity. RU/FA-800 exhibits the highest conversion due to higher surface loading of Ru, stronger NH3 adsorption and least acid sites. (C) 2008 Elsevier B.V. All rights reserved.