Influence of the reduction temperature on catalytic activity of Co/TiO2 (anatase-type) for high pressure dry reforming of methane Original Research Article

0.5 wt.% Co/TiO2 was prepared by incipient wetness impregnation with Co(NO3)2·6H2O and TiO2, which contains only anatase as crystal structure. The influence of reduction temperature (973–1223 K) on the catalytic activity of the 0.5 wt.% Co/TiO2 was investigated for the CH4/CO2 reaction under 2.0 MPa mainly at a space velocity (SV) of 6000 ml g−1 h−1. Co/TiO2 reduced below 1123 K lost its activity completely at the beginning of the reaction. The results of TPO revealed that large amounts of coke (≧2.9 wt.% carbon for 24 h) were deposited on the catalysts during the CH4/CO2 reaction. On the other hand, Co/TiO2 reduced at and above 1123 K kept relatively stable activity for 24 h and did not show significant amounts of deposited coke (≦0.25 wt.% carbon). The natures causing different catalytic behavior among the catalysts were discussed with the results of TEM, XRD, and TPR. In addition, slow deactivation of the Co/TiO2 reduced at 1123 K, probably due to the oxidation of the metallic cobalt, was inhibited by the addition of small amount of ruthenium (Ru/Co=0.05) and it was found that the strong resistance to the coking of the Co/TiO2 reduced at 1123 K was retained after the addition of ruthenium.