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In order to investigate the effect of cerium oxide addition, Cu-ZnO-CeO2 catalysts were prepared using co-precipitation method for water gas shift (WGS) reaction. A series of Cu-ZnO-CeO2 catalyst with fixed Cu Content (50 wt%, calculated as CuO) and a given ceria content (e.g., 0, 5, 10, 20, 30, 40 wt%, calculated as CeO2) were tested for catalytic activity at a GHSV of 95,541 h -1 , and a temperature range of 200 to 400 ℃. Cu-ZnO-CeO2 catalysts were characterized by using BET, SEM, XRD, H2-TPR, and XPS analysis. Varying composition of Cu-ZnO-CeO2 catlysts led the difference characteristics such as Cu dispersion, and binding energy. The optimum 10 wt% doping of cerium facilitated catalyst reduction at lower temperature and improved the catalyst performance greatly in terms of CO conversion. Cerium oxide added catalyst showed enhanced activities at higher temperature when it compared with the catalyst without cerium oxide. Consequently, ceria addition of optimal composition leads to enhanced catalytic activity which is attributed to enhanced Cu dispersion, lower binding energy, and hindered Cu metal agglomeration.

>> Nanorod and particle shape CeO2 were synthesized via hydrothermal process and precipitation method, respectively, and used as supports of Pt catalyst for water gas shift (WGS) reaction. Three different durations (12, 48, and 96h) for hydrothermal process were applied for the preparation of nanorod type CeO2. 1.0 wt% of Pt was loaded on the prepared supports with incipient wetness method prior to the catalytic activity tests that were carried out at a GHSV of 95,541 h -1, and a temperature range of 200 to 360 o C. Varying duration of hydrothermal process led to the difference in physical characteristics of CeO2 nanorods, such as aspect ratio, BET surface area, pore diameter, and pore volume. Consequently, the catalytic activities of Pt/CeO2 nanorods were affected by the physical characteristics of the supports and appeared to be in the order of Pt/CeO2(12) > Pt/CeO2(48) > Pt/CeO2(96). The comparison of the catalytic activities and results of the analysis (XPS, XRD, SEM, BET and TPR) for the supports revealed that the activity of the catalysts depends on chemical states of the Pt and the support materials in the temperature range that is lower than 280 o C. However, the activity is rather dependent on the physical characteristic of the supports because the increased gas velocity limits the mass transfer of reactants in micropores of the supports.