Ni-Cu/γ-Al_2O_3催化剂上月桂腈的加氢性能

Hydrogenation Performance of Lauronitrile over Ni-Cu Supported γ-Al_2O_3 Catalyst

用Cr和Na对浸渍法制备的γ-Al2O3负载Ni-Cu催化剂进行改性,用H2-TPD和CO2-TPD技术表征催化剂H2吸附能力和碱性质,并考察了其对月桂腈加氢反应的催化性能.结果表明,Cr和Na改性后催化剂H2吸附能力显著增强,碱性质得到调节,Ni-Cu-Cr-Na/γ-Al2O3催化剂具有最大H2吸附能力和最大低强度碱量及最大活性,月桂腈转化率为98%,伯胺选择性为99.2%.优化反应条件为:氢分压2.0MPa,反应温度70℃,反应时间30min,搅拌转速600r/min.反应10次后,月桂腈的转化率由98%降为94.8%,伯胺的选择性维持在98%以上.

A series of Ni-Cu/γ-Al2O3 catalysts were prepared by impregnation method. After modification by Na and Cr, the catalysts were characterized by TPD technology using H2 and CO2 as probe molecules to test their hydrogen adsorption abilities and alkali properties. And their catalytic performances were measured in hydrogenation of lauronitrile. The results show that hydrogen adsorption amount of catalyst was enhanced and the alkali nature adjusted observably, while the sample Ni-Cu-Cr-Na/γ-Al2O3 owned the most hydrogen adsorption amount as well as the most low temperature alkali scalar. The catalyst Ni-Cu-Cr-Na/γ-Al2O3 was provided with the best catalytic abilities of hydrogenation, with conversion rate of lauronitrile 98% and selectivity of primary dodecylamine 99.2% under the optimal reaction conditions of hydrogen fractional pressure 2.0 MPa, reaction temperature 70℃, reaction time 30 min, and stirring speed 600 r/min. The stability tests show that the result reacting for 10 times was conversion rate of lauronitrile 94.8% and selectivity of primary amine kept highly above 98.0%.