The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2...The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2-Al2O3-I sample was also used. Ni/SiO2-I was a non-acidic catalyst containing large Ni^0 particles of low interaction with the support, while Ni/SiO2-A was an acidic catalyst due to the presence of Ni^2+ species in Ni phyllosilicates of low reducibility. Ni/SiO2-I formed essentially butylamine (80%), and dibutylamine as the only byproduct. In contrast, Ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on Ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to Ni^0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.展开更多
The transition metals （Cu, Co, and Fe） were applied to modify Ni/Ce0.2Zr0.1Al0.7Oδ catalyst. The effects of transition metals on the catalytic properties of Ni/Ce0.2Zr0.1Al0.7Oδ autothermal reforming of methane we...The transition metals （Cu, Co, and Fe） were applied to modify Ni/Ce0.2Zr0.1Al0.7Oδ catalyst. The effects of transition metals on the catalytic properties of Ni/Ce0.2Zr0.1Al0.7Oδ autothermal reforming of methane were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. Tests in autothermal reforming of methane to hydrogen showed that the addition of transition metals （Cu and Co） significantly increased the activity of catalyst under the conditions of lower reaction temperature, and Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ was found to have the highest conversion of CH4 among all catalysts in the operation temperatures ranging from 923 K to 1023 K. TPR, XRD and XPS measurements indicated that the cubic phases of CexZr1-xO2 solid solution were formed in the preparation process of catalysts. Strong interaction was found to exist between NiO and CexZr1-xO2 solid solution. The addition of Cu improved the dispersion of NiO, inhibited the formation of NiAl2O4, and thus significantly promoted the activity of the catalyst Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ展开更多
The activities of Ni catalysts with different supports in methane decomposition have been studied. The activity order of the catalysts is Ni/SiO 2>Ni/MgO-Al 2O 3>Ni/CaO-Al 2O 3>Ni/α-Al 2O 3 and the interacti...The activities of Ni catalysts with different supports in methane decomposition have been studied. The activity order of the catalysts is Ni/SiO 2>Ni/MgO-Al 2O 3>Ni/CaO-Al 2O 3>Ni/α-Al 2O 3 and the interaction between Ni and the support is in the order of Ni/SiO 2<Ni/MgO-Al 2O 3<Ni/CaO-Al 2O 3<Ni/α-Al 2O 3. It is thus concluded that the weaker the interaction between Ni and support, the higher the activity of the catalyst. It was also found that the activity of the silica supported Ni-catalyst was increased with increase in its average pore radius and predominance pore radius.展开更多
基金the Universidad Nacional del Litoral (UNL)Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT ), Argentina, for the financial support of this work
文摘The liquid-phase hydrogenation of butyronitrile to saturated amines was studied on silica- supported Ni catalysts prepared by either incipient-wetness impregnation (Ni/SiO2-I) or ammonia (Ni/SiO2-A) methods. A Ni/SiO2-Al2O3-I sample was also used. Ni/SiO2-I was a non-acidic catalyst containing large Ni^0 particles of low interaction with the support, while Ni/SiO2-A was an acidic catalyst due to the presence of Ni^2+ species in Ni phyllosilicates of low reducibility. Ni/SiO2-I formed essentially butylamine (80%), and dibutylamine as the only byproduct. In contrast, Ni/SiO2-A yielded a mixture of dibutylamine (49%) and tributylamine (45%), being the formation of butylamine almost completely suppressed. The selective formation of secondary and tertiary amines on Ni/SiO2-A was explained by considering that butylamine is not release to the liquid phase during the reaction because it is strongly adsorbed on surface acid sites contiguous to Ni^0 atoms, thereby favoring the butylimine/butylamine condensation to higher amines between adsorbed species.
基金This work was supported by Guangdong Natural Science Foundation of China (030514)Science and Technology Programs of Guangdong Province of China (2004B33401006)
文摘The transition metals （Cu, Co, and Fe） were applied to modify Ni/Ce0.2Zr0.1Al0.7Oδ catalyst. The effects of transition metals on the catalytic properties of Ni/Ce0.2Zr0.1Al0.7Oδ autothermal reforming of methane were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. Tests in autothermal reforming of methane to hydrogen showed that the addition of transition metals （Cu and Co） significantly increased the activity of catalyst under the conditions of lower reaction temperature, and Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ was found to have the highest conversion of CH4 among all catalysts in the operation temperatures ranging from 923 K to 1023 K. TPR, XRD and XPS measurements indicated that the cubic phases of CexZr1-xO2 solid solution were formed in the preparation process of catalysts. Strong interaction was found to exist between NiO and CexZr1-xO2 solid solution. The addition of Cu improved the dispersion of NiO, inhibited the formation of NiAl2O4, and thus significantly promoted the activity of the catalyst Ni/Cu0.05Ce0.2Zr0.1Al0.65Oδ
文摘The activities of Ni catalysts with different supports in methane decomposition have been studied. The activity order of the catalysts is Ni/SiO 2>Ni/MgO-Al 2O 3>Ni/CaO-Al 2O 3>Ni/α-Al 2O 3 and the interaction between Ni and the support is in the order of Ni/SiO 2<Ni/MgO-Al 2O 3<Ni/CaO-Al 2O 3<Ni/α-Al 2O 3. It is thus concluded that the weaker the interaction between Ni and support, the higher the activity of the catalyst. It was also found that the activity of the silica supported Ni-catalyst was increased with increase in its average pore radius and predominance pore radius.
