Effects of preparation conditions of Au/FeOx/Al2O3 catalysts prepared by a modified two-step method on the stability for CO oxidation

Composite oxide FeOx/Al2O3-supported gold catalysts were prepared by a modified two-step method. The effects of preparation conditions on the initial catalytic activity and long-time stability were studied for CO oxidation. XRD, XPS and in situ FTIR were employed to investigate the state of FeOx and the species on the catalyst surface. The results showed that Au/FeOx/Al2O3 catalysts prepared by this method exhibited high activity and high stability in a wide pH value range. Calcination pretreatment was proved to be beneficial to improving the activity and stability. The beneficial effects of FeOx acting as a structural promoter could be ascribed to the ability to supply active oxygen species. As the precursor of FeOx, Fe(NO3)3 is superior to FeCl3 for obtaining higher stability.