| dc.description.abstract | Nanosized gold catalyst has been reported to be a good catalyst for the liquid phase hydrogenation reactions due to their excellent activity and selectivity. In this study, various additives (FeOx, AlOx, CeO2, MgO, MnOx, ZrO) were added into Au/TiO2 catalyst.. The modified-TiO2 support was prepared by incipient-wetness impregnation0. Gold catalysts were prepared by deposition-precipitation method with 4wt. % Au loading. The activity of the modified catalyst was tested for the hydrogenation of p-chloronitrobenzene. These catalysts were characterized by inductively-coupled-plasma-mass spectrometry, X–ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and temperature programmed reduction. The catalytic properties of gold based catalysts were studied on hydrogenation of p–chloronitrobenzene(p-CNB). The conditions for hydrogenation reaction were 1.2 MPa H2 pressure, 353 K reaction temperature and 500 rpm stirring speed. Methanol was used as the solvent, the concentration of p-CNB was 0.2 M (2.54g p–CNB in 80 ml methanol) and the amount of gold based catalyst was 0.5g. For modified gold catalysts, Fe-doped ones were better than the other catalysts, and it had the highest activity and selectivity. A series of Au catalysts supported on FeOx-TiO2 with various Fe contents were prepared. The iron oxide in Au/FeOx-TiO2 played the role of a textural promoter, prevents from sintering of gold particles. The results showed that the additive of Fe could prevent Au0 from being oxidized, increased the active sites and enhanced catalytic activity. Au/ FeOx-TiO2 with Fe/Ti atomic ratio of 4/6 exhibited the highest activity among the series of Au/ FeOx-TiO2. It could be concluded that adding suitable iron amount showed the best performance, and could promote the activity of Au catalyst effectively.
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