纳米CeNi/Al_2O_3催化剂的结构和性能

Structure and Properties of Nano -CeNi/Al_2O_3 Catalyst

利用H2+Ar等离子体法制备具有Ce壳的纳米Ni粒子,并用球磨法负载到载体Al2O3上制得CeNi/Al2O3催化剂。同时用浸渍法制备CeNi/Al2O3催化剂。利用SEM,BET,XRD,TPR等方法,对两种催化剂进行了表征。实验证明焙烧后纳米CeNi粒子被完全氧化,且分布在载体表面,在280℃能完全还原;而浸渍法制备的催化剂的活性组分和载体结合力较强,难以还原。在还原温度低于500℃时,纳米CeNi/Al2O3催化剂的苯加氢活性高于浸渍法制备的催化剂。

Ni nanoparticles with Ce shell were prepared by H_2+Ar arc plasma method and loaded on Al_2O_3 support by ball milling.CeNi/Al_2O_3 catalyst was prepared by ordinary impregnation.The two kinds of catalyst were studied by means of SEM,XRD,BET and TPR technolgies.CeNi nanoparticles were oxidized after calcination and mainly dispersed on outside surface of Al_2O_3 support.The oxidized nanoparticles could be reduced at 280 ℃.On the contrary,the Al_2O_3 supported Ni nanoparticles strongly interacted with support,so it was difficult to be reduced.When reduction temperature was below 500 ℃ nano-CeNi/Al_2O_3 catalyst possessed excellent benzene hydrogenation activity comparing with CeNi/Al_2O_3 catalyst.