Ni/Fe物质的量的比对Ni-Fe催化剂表面性质和二硝基甲苯加氢活性的影响  

Influence of Ni/Fe Molar Ratio on Surface Properties of Ni-Fe Catalysts and Hydrogenation Performance of Dinitrotoluene

作　　者：郝志强[1] 于智慧 李忠[1] 

机构地区：[1]太原理工大学煤科学与技术教育部与山西省重点实验室,太原030024 [2]赛鼎工程有限公司,太原030024

出　　处：《无机化学学报》2015年第8期1571-1580,共10页Chinese Journal of Inorganic Chemistry

基　　金：国家"973"计划(No.2012CB723105)资助项目

摘　　要：采用Fe粉置换氯化镍溶液中的Ni2＋制备了Ni-Fe催化剂,并应用于催化二硝基甲苯加氢合成甲苯二胺的反应中。运用XRD、低温氮吸附-脱附、H2-TPD、XPS和TEM等技术手段对不同Ni/Fe物质的量的比（nNi/nFe）下催化剂进行了表征。结果表明,nNi/nFe对Ni-Fe催化剂表面性质影响显著。当nNi/nFe为1∶4时,Fe抑制Ni氧化的作用达到最大,Ni-Fe催化剂化学氢吸附量和活性物种Ni的分散度分别达到了0.16 mmol·g-1和23%,催化剂性能得到较大的提升。在优化的催化剂制备条件下,DNT（二硝基甲苯）的转化率和TDA（甲苯二胺）的选择性分别达到了～100%和99%。另外,对Ni-Zn漆原镍（Urushibara Ni）催化剂和Ni-Fe催化剂催化DNT加氢反应进程进行了研究,发现它们有相同的加氢中间产物,但反应不同阶段的催化速率存在差异。Ni-Fe catalysts were prepared via the replacement reaction of NiC12 by Fe and used for the selective hy- drogenation of dinitrotoluene （DNT） in liquid phase. The influences of Ni/Fe molar ratio （nNi/nFe） on the surface prop- erties and catalytic performance of Ni-Fe catalysts were investigated. The characterization results from XRD, Low temperature nitrogen adsorption -desorption, H2-TPD, XPS and TEM show that nNi/nFe has a significant effect on the surface properties of Ni-Fe catalysts. When nNi/nFe is 1：4, the effect of Fe inhibition on the oxidation of nickel is more apparent, the chemical adsorption of hydrogen is 0.16 mmol·g-1 and the dispersion of active species Ni achieves 23%. The performance of Ni-Fe catalysts is greatly improved. Under the optimized catalysts preparation conditions, the conversion of DNT （dinitrotoluene） and the selectivity of TDA （toluenediamine） could reach～100% and 99%, re- spectively. In addition, Ni-Zn Urushibara nickel catalysts and Ni-Fe catalysts have-the same catalytic hydrogena- tion-pathway but different catalytic reaction rate in a different reaction stages.

关 键 词：Ni-Fe催化剂 二硝基甲苯 甲苯二胺 催化加氢 

分 类 号：O643.3[理学—物理化学] O614.81[理学—化学]