Raney-Ni-Mo/Al_2O_3催化剂的制备及其催化茚饱和加氢性能

Preparation of the Supported Raney-Ni-Mo/Al_2O_3 Catalyst and Its Catalytic Hydrogenation of Indene

以含钼为1.5%的镍-铝合金粉与拟薄水铝石按质量比为1∶1的比例,经成型、焙烧、浸取活化制备了负载型Raney-Ni-Mo/Al2O3加氢催化剂,通过XRD、BET、TG-DTA及SEM等手段对催化剂进行分析表征,并以茚加氢生成茚满的反应为探针,采用连续固定床加氢反应装置对所制备的催化剂加氢性能进行了评价.结果表明:成型合金A lloy-Ni-Mo/Al2O3的焙烧温度对于浸取活化后的Raney-Ni-Mo/Al2O3催化剂的抗压强度至关重要,比较适宜的焙烧温度为860℃,在该温度下合金中富铝相NiAl3向贫铝相Ni2Al3转变不仅有利于提高催化剂的加氢活性,而且金属铝被氧化生成α-Al2O3,使得制备的Raney-Ni-Mo/Al2O3加氢催化剂的强度能满足固定床装填要求.在反应压力2.0 MPa、温度180℃、WHSV=2 h-1、氢油比(V/V)为300∶1条件下,Raney-Ni-Mo/Al2O3催化剂催化茚加氢生成茚满的转化率在所考察的1 000 h周期内均高于90%,表明该催化剂具有较好的加氢活性及其活性稳定性.

The Raney-Ni-Mo/Al2O3 catalysts for hydrogeneration of unsaturated organic compounds were prepared by kneading and extruding the nickel-aluminum alloy powder with pseudoboehmite at a mass ratio of 1 ： 1, calcined at different temperatures and leached out the aluminum with sodium hydroxide solution. XRD, BET, TG-DTA, and SEM measurement methods were used to analyze and determine the characteristics of the catalysts. Meanwhile, the catalytic hydrogeneration preformanee of the prepared catalysts was investigated in a continuous fixed-bed hydrogen- ation reactor with indene hydrogenation reaction as a reaction probe. The results show that the calcination tempera- ture plays an importment role in the compressive strength of the supported Raney-Ni-Mo/Al2O3 , and the more ap- propriate calcination temperature is 860 ℃, the crystal phase transformation from NiAl3 phase to Ni2Al3 phase at that appropriate temperature not only improve the hydrogenation activity of the prepared catalyst, and also enhance the compressive strength of the supported Raney-Ni-Mo/Al2O3 by oxidizing aluminum to generate α-Al2O3 phase. In addition, the supported Raney-Ni-Mo/Al2O3 catalyst used to the hydrogeneration of indene exhibits a high catalytic activity and activity stability. Under the reaction conditions of reaction pressure 2.0 MPa, inlet temperature 180 ℃, fresh oil space velocity 2 h-1, and volume ratio of hydrogen to oil 300 ： 1, the conversion of indene was higher than 90% in the reaction period of 1 000 h.