Catalyzing effects of impregnated Rh, Pt and Ce on Ni(II)-bearing ferrite (NF) activated with H-2 have been studied for CO2 decomposition to carbon at 300 degrees C. The activation rate of the Rh- or Pt-impregnated NF with H-2 gas was about 1.6 times as large as that of the NF alone at 300 degrees C. At 250 degrees C, the Rh- and Pt-NFs were also activated at 1.6 and 1.3 times higher rates than that of NF control, respectively. The activation of NF was, however, not enhanced by the impregnation of Ce. The rates of CO2 decomposition using these activated materials were 1.2-3.0 times as large as that of the activated NF. The effect of metal impregnation on the activation and CO2 decomposition increased in the order of Ce < Pt < Rh. This catalyzing effect is attributed to hydrogen and oxygen spillovers through accelerated dissociations of H-2 and CO2 molecules, respectively, on the surface of Rh, Pt or Ce deposited on the NF.