CO and CO₂ Methanation Over Ni/γ-Al₂O₃ Prepared by Deposition-Precipitation Method.

Various Ni catalysts supported on γ-Al₂O₃ were prepared by a wet impregnation (WI) method and deposition-precipitation (DP) method with different precipitants and applied to CO and CO₂ methanation. The prepared catalysts were characterized by various techniques including nitrogen physisorption, X-ray diffraction (XRD), temperature-programmed reduction with H₂ (H₂-TPR), H₂ chemisorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Irrespective of kinds of precipitant, the Ni/γ-Al₂O₃ catalysts prepared with a DP method showed a remarkable enhanced catalytic performance in CO and CO₂ methanation compared with the Ni/γ-Al₂O₃ catalyst prepared with a WI method owing to the higher catalytic active surface area (CASA).