A series of Cu-based catalysts were prepared and examined for the reductive amination of triacetoneamine with n-butylamine, thereinto, Cu-Cr-La/c-Al 2 O 3 showed excellent results. The catalysts were studied by XRD, XPS, H 2 -TPR and NH 3 -TPD. It was found that doped Cr remarkably enhanced the activity of Cu/c-Al 2 O 3 due to better dispersion of Cu 0 , which is believed to be the active site for the reductive amination. Additionally, it was obvious that introduction of La to Cu-Cr/c-Al 2 O 3 led to a higher selectivity and longer lifetime. The reaction parameters were optimized and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine was obtained in a yield of 94%.

A series of Pd-based catalysts were prepared and examined for the amination of 2,6-dimethylphenol in a fixedbed reactor. The best results were obtained for Pd/Al2O3-BaO with a conversion of 99.89% and a selectivity of 91.16%. These catalysts were characterized using BET, XRD, XPS, TEM and NH3-TPD. Doped BaO not only improved the dispersion of the Pd particles but also decreased the acidity of the catalyst, which remarkably enhanced the selectivity and stability of the catalyst. The generality of Pd/Al2O3-BaO for this kind of reaction was demonstrated by catalytic aminations of o-and p-alkyl phenols.

Continuous synthesis of N-methylhomopiperazine over Cu-Cr-Mg/c-Al 2 O 3 has been developed. The doped Cr improves the dispersion of the Cu 0 particles and inhibits the generation of CuAl 2 O 4 so that the Cu 0 particles are retained as the active sites. Doped Mg neutralizes the strong acid sites in Cu 20 Cr 10 Mg 10 /c-Al 2 O 3 , and led to a decrease in coking side reactions. The reaction parameters were optimized and N-methylhomopiperazine was obtained in a yield of 66%.

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