Activity of Au/Fe2O3–TiO2 catalyst for preferential CO oxidation

• The catalytic activity of Au catalyst in PROX reaction was developed by Fe2O3–TiO2.
• Metal atomic ratio, calcination and Au loading amount affect the catalyst nature.
• The gas feed composition could affect the catalyst surface and its activity.

A series of Au supported on Fe2O3–TiO2 catalysts were prepared, characterized and investigated the catalytic activity in the preferential CO oxidation (PROX) under a H2-rich stream. The effects of the different metal support ratio, the calcination temperature, the gold loading, and the pre-treatment condition were studied on both the characteristics and catalytic activity of the catalysts. The results obviously showed that 1% Au/Fe2O3–TiO2 (1:4) exhibited higher CO conversion than the 1% Au/TiO2 and 1% Au/Fe2O3 catalysts, especially temperature lower than 100 °C, which due to the formation of reducible gold species at lower temperature. TPR results suggested the improvement of Au–Au and metal–metal (in support) interaction. Additionally, XPS spectra suggested the Au0 could be the predominant active site. The effect of O2 pretreatment showed a negative effect in both activity and selectivity which suggested the formation of adsorbed oxygen species on the surface of the catalyst. Moreover, the deactivation was affected by injection H2O, CO2 or the combination of CO2–H2O into the typical feed.