Abstract:
In this research, the catalytic acivity of Au/CeO2 catalysts for the low-temperature water-gas shift reaction (LT-WGS) was studied on both lab-scale and bench-scale experiments. A series of Au/CeO2 catalysts was prepared by deposition-precipitation method. The effects of space velocity, H2 pretreatment, type of CeO2 support, H2O/CO ratio, and H2 mixing in the reactant on the catalytic performance were investigated over a wide temperature range 100-350C under atmospheric pressure. The catalytic activity of Au/CeO2 catalysts was also compared to that of a commercial CuO/ZnO/Al2O3 catalyst. It was found that 2%Au/CeO2 (high surface area) pretreated with H2 manifested the best activity; however, its activity was much lower than the commercial catalyst. The influence of H2 on the activity of Au/CeO2 in the LTWGS was also studied. It was found that the presence of H2 in the feed significantly decreased the activity of the catalyst. The stability of 2% Au/CeO2 was also investigated. The CO conversion was decreased 10% after 500 minutes. In addition, both the 2% Au/CeO2 and the commercial catalysts were tested in a WGS reactor with a fuel processor, utilizing natural gas as a feed. Finally, the Au/CeO2 catalysts were characterized by XRD, TPR, TEM, and BET.
