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用比表面和孔体积测定、XRD和程序升温还原(TPR)方法研究了一系列不同制备条件对Ni在Al_2O_3表面上的分配形态及其对CO加氢反应催化性能的影响.实验发现,本文所用制备条件对催化剂的比表面、孔体积及孔径分布无显著的影响.浸渍时间愈长,催化剂上能在较低温度下还原的物种愈少,催化剂上CO的加氢活性愈低;在浸渍前对载体作室温抽空处理后制得的催化剂上,Ni在Al_2O_3表面是高度分散的,这一高度分散物种易于在低温下还原,使该催化剂具有很高的CO加氢活性和生成CH_4选择性;载体的抽空温度及对载体加热均对Ni物种形态及其分配、催化剂性能有明显影响.
The effects of a series of different preparation conditions on the distribution of Ni on the surface of Al 2 O 3 and its catalytic performance for CO hydrogenation were investigated by specific surface area and pore volume measurement, XRD and temperature-programmed reduction (TPR) .It was found that, The preparation conditions had no significant effect on the specific surface area, pore volume and pore size distribution of the catalyst.The longer the immersion time, the less the species can be reduced at a lower temperature on the catalyst, the lower the hydrogenation activity of CO on the catalyst; Ni on the surface of Al 2 O 3 is highly dispersed, and this highly dispersed species is easy to reduce at low temperature, so that the catalyst has high CO hydrogenation activity and CH 4 selectivity. The evacuation temperature of the support and the heating of the support all have obvious effects on the morphology and distribution of the Ni species and the catalyst performance.