| Abstract: | The Co-incorporated Ce_(1-x)Zr_xO_2 catalysts were prepared by co-precipitation for carbon dioxide reforming of methane. The ratio of Ce to Zr was varied to optimize the performances of co-precipitated Co-Ce-Zr-O_x catalysts. The prepared catalysts were characterized by various physico-chemical characterization techniques including TPR, X-ray diffraction, N2 adsorption at low temperature, XPS and CO_2-TPSR. The co-precipitated Co-Ce_(0.8)Zr_(0.2)O_2 sample containing 16% CoO exhibited a higher catalytic activity among the five catalysts, and the activity was maintained without significant loss during the reaction for 60 h. Under the conditions of 750 ℃, 0.1 MPa, 36000 ml/(h·g_(cat)), and CO_2/CH_4 molar ratio of 1 : 1, the CO_2 conversion over this catalyst was 75% while the CH_4 conversion was 67%. The cubic Ce_(0.8)Zr_(0.2)O_2 facilitated a higher dispersion and a higher reducibility of the cobalt component, and the apparent activation energy for Co-Ce_(0.8)Zr_(0.2)O_2 sample was 49.1 kJ/mol in the CO_2/CH_4 reforming reaction. As a result, the Co-Ce_(0.8)Zr_(0.2)O_2 sample exhibited a higher activity and stability for the reforming of CH_4 with CO_2. |
