抄録
Layered double hydroxides (LDH's), M (II) 1-x M (III) x (OH) 2 (CO3) x/2·nH2O (M (II) =Mg, Mn, Co, Ni, Cu, Zn, M (III) =Al, Fe) were prepared by the conventional coprecipitation method. The structures of the samples were analyzed by XRD and FT-IR measurements. Methanation of the sorbed CO2-3 ions was carried out using a thermo-balance system in H2 Gas flow of the atmospheric pressure. Apparent CH4 evolution was observed in the cases of Ni/Al-, Ni/ Fe-, Co/Al- and Co/Fe-systems. Following features ware found concerning to catalytic effects: (1) Nickel-containing LDH's have high activity for methanation, (2) Cobalt-containing LDH's have relatively low methanation activity, (3) The existence of Fe (III) is effective both on lowering the methanation temperature and on increasing conversion to CH4. Methane generation from these compounds was interpreted in terms of thermodynamic property of metals composing the brucite layers.
