Comparison of the effects of the catalyst preparation method and CeO2 morphology on the catalytic activity of Pt/CeO2 catalysts for the water-gas shift reaction

In this study, the effects of the catalyst preparation method and CeO(2)particle morphology of Pt/CeO(2)catalysts for the water-gas shift reaction are compared. CeO(2)supports having nanorod and nanocube morphologies were prepared. Over both types of supports, 1 wt% Pt was loadedviaeither the incipient wetness impregnation (IWI) method or the strong electrostatic adsorption (SEA) method. In total, four types of Pt/CeO(2)catalysts were prepared, and these were characterized using various techniques and tested for the water-gas shift reaction. The cube-shaped-CeO2-based catalysts showed higher catalytic activities than the rod-shaped-CeO2-based catalysts due to the higher dispersion of Pt(0)regardless of the catalyst preparation method. From the viewpoint of the catalyst preparation method, the IWI-prepared catalysts showed higher catalytic activity than the SEA-prepared catalysts regardless of the morphology of CeO(2)because of the larger amount of oxygen vacancies induced by the strong interaction between PtO(x)and CeO2. These results highlight the fact that the catalyst preparation method and the morphology of the CeO(2)support strongly affect the key factors (Pt(0)dispersion and number of oxygen vacancies) separately, which are directly related to the catalytic activity in the water-gas shift reaction. It also confirms that both key factors should achieve high values to attain high catalytic activity.