| In Triton X-100/n-hexanol / cyclohexane / water and CTAB/n-hexanol / water inverse microemulsions, Au/Fe2O3 catalysts were prepared by controlling several major parameters. The water-gas shift (WGS) activities of the catalysts were studied. the structure and properties of the catalysts prepared by different methods were also studied by XRD,N2 adsorption,H2-TPR,TEM,DRS and XPS .The results of WGS activity indicated that the variety of the synthesis parameters in CTAB inverse microemulsion had little effect on the activity; the activities of these catalysts were all very low. For Triton X-100 series catalysts, the activities of Au/Fe2O3 catalysts were much higher than that of Fe2O3 support. The activity of the sample calcinated at 250 ℃ was the best among the calcination temperatures studied. On the other hand, the activity decreased with increasing the weight ratio of water to surfactant rw and the concentration of surfactant W. In addition, the activity first increased with increasing gold content of the sample, then decreased after reaching a certain value upon further increasing the gold content. The optimum results showed that when the gold content is 3 %, the conversion of the CO reached 99.5 %.On the basis of XRD,TPR and XPS results, it had been proposed that Au(Ⅲ) and Au were the active species for low WGS reaction, but Au-FeOX solid solution for high temperature WGS reaction. TEM results suggested that the size of the gold particle in Au/Fe2O3 catalysts prepared by microemulsion method was less than 10 nm, gold particles were highly dispersed on the support and deposited with its 111 plane in contact with support. The catalytic activitydifferences among Triton X-100 series catalysts showed that the smaller the size of gold particle was,the higher the contents of Au(Ⅲ) and dispersion of gold were,the higher the activity for low temperature WGS reaction was. The more the amounts of the Au-FeOX defects were, the better the activity for high temperature WGS reaction was.
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