Nanostructured Au–CeO2 catalysts for low-temperature water–gas shift

The composite system of nanostructured gold and cerium oxide, with a gold loading 5–8 wt%, is reported in this work as a very good catalyst for low-temperature water–gas shift. Activity depends largely on the presence of nanosized ceria particles. Various techniques of preparation of an active catalyst are disscussed. The presence of gold is crucial for activity below 300 ◦C. A dramatic effect of gold on the reducibility of the surface oxygen of ceria is found by H2-TPR, from 310–480 ◦C to 25–110 ◦C. All of the available surface oxygen was reduced, while there was no effect on the bulk oxygen of ceria. This correlates well with the shift activity of the Au–ceria system.