Low Temperature Water-Gas Shift Reaction on Au-CeO2/Al2O3 Catalysts

Abstract

The low temperature water gas shift activities of Au-CeO2/Al2O3 catalysts were studied in this work. The catalysts were prepared by impregnation of CeO2 on alumina support followed by the homogeneous deposition precipitation of Au on CeO2/Al2O3. The catalysts were tested in a microflow reaction system. It was found that the activity of the catalyst increased with increasing Ce loading from 2.5 wt.% to 10 wt.% significantly while the increase in the activity was minor with the further increase of the ceria to 20 wt.%. The increasing Au content from 1 wt.% to 3 wt.% inversely affected the activity but the conversion increased with increasing Au to 5 wt.%. It was observed that the activity of 5wt.%Au/20wt.%Ce/Al2O3 decreased with increasing CO concentration. On the other hand, the CO conversion was increased with increasing H2O in the feed (significantly up to 10% H2O and then slightly after that). The 15% CO2 in the feed decreased catalytic activity slightly while the negative effect of 60% H2 was more dramatic. The presence of both CO2 and H2 in the feed together resulted the lowest conversion as expected.