Ni-W-P非晶态合金催化剂的制备及催化硝基苯液相加氢性能

采用化学还原法制备镍-钨-磷(Ni-W-P)非晶态合金催化剂，通过X射线衍射仪(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、物理吸附仪(BET法)、差示扫描量热仪(DSC)等技术对催化剂结构与性能进行了表征。考察了催化剂中W含量和反应工艺条件对硝基苯液相加氢制苯胺性能的影响。结果表明，随着助剂W的加入，Ni-W-P非晶态合金的无序程度增大，比表面积增大，颗粒粒径减小，热稳定性得到提高；硝基苯的转化率随W含量的增加先增大后保持不变，苯胺的选择性先增大后减小，当W的添加量为6%(摩尔分数)时，硝基苯转化率和苯胺选择性均为100%。在优化的反应条件下：催化剂用量75%(催化剂相对于硝基苯的用量)，H₂压力1.0 MPa，反应温度100 ℃，反应时间90 min，硝基苯转化率和苯胺选择性均达到100%。催化剂循环使用5次后，硝基苯转化率高达99%，苯胺选择性保持在97%以上。

Preparationof Ni-W-P Amorphous Catalysts andTheir Catalytic Performance in Nitrobenzene Hydrogenation

Abstract: A series of Ni-W-P amorphous alloy catalyst were prepared by chemical reduction method, and which was characterized by XRD, BET, SEM and DSC. The effects of amount of W and hydrogenation conditions were investigated through the hydrogenation of nitrobenzene to aniline. The results showed that W additives could enhance the extent of long-range disorder, increase the specific surface area, decrease the particle size, and improve the thermal stability. Along with the increasing of the amount of W, the conversion of nitrobenzene firstly increased then remained at same level and the selectivity of aniline firstly increased then decreased. The conversion of nitrobenzene and the selectivity of aniline were both 100% when the amount of W was 6%.The conversion of nitrobenzene and the selectivity of aniline were all 100% under optimized reaction conditions of which the amount of catalyst was 0.15g, the pressure of H2 was 1.0MPa, the temperature was 100℃, the reaction time was 90 minutes. After the catalyst was used repeatedly 5 times，the conversion of nitrobenzene and selectivity of aniline were 99% and 97% respectively.