Abstract: Ni-based catalysts with SiO₂, γ-Al₂O₃, CaO, and TiO₂ as supports and MgO-7.5% Ni/γ-Al₂O₃ catalysts with different contents of MgO were prepared. The structure of the catalysts was characterized by powder X-ray diffraction and N₂ adsorption-desorption measurements. The performance of the catalysts in the steam reforming of rice straw biomass to syngas was evaluated. The effects of reaction conditions on the activity of the catalysts were also investigated. Ni-based catalysts supported on γ-Al₂O₃ had higher catalytic activity than the catalysts supported on TiO₂, CaO, and SiO₂. The yield of H₂ reached 1071.3 ml H₂/g biomass and the ratio of H₂ to CO was 1.4:1 over a 7.5% Ni/γ-Al₂O₃ catalyst. Addition of MgO to the 7.5% Ni/γ-Al₂O₃ catalyst improved its catalytic activity. The yield of H₂ reached 1194.6 ml H₂/g biomass and the ratio of H₂ to CO was 3.9:1 over the 1.0% MgO-7.5% Ni/γ-Al₂O₃ catalyst. MgO not only improves the steam reforming reaction of Ni-based catalysts, but can also promote the water-gas shift reaction. This method shows promise for production of H₂-rich syngas from biomass.

Key words: Nickel-based catalyst, Rice straw, Steam reforming, Syngas, Hydrogen