| 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 |
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| 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。 |
| 关键词: Ni-Fe催化剂 二硝基甲苯 甲苯二胺 催化加氢 |
| 基金项目: 国家"973"计划(No.2012CB723105)资助项目。 |
| Abstract: Ni-Fe catalysts were prepared via the replacement reaction of NiCl2 by Fe and used for the selective hydrogenation of dinitrotoluene (DNT) in liquid phase. The influences of Ni/Fe molar ratio (nNi/nFe) on the surface properties 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%, respectively. In addition, Ni-Zn Urushibara nickel catalysts and Ni-Fe catalysts have~the same catalytic hydrogenation~pathway but different catalytic reaction rate in a different reaction stages. |
| Keywords: Ni-Fe catalyst dinitrotoluene toluenediamine catalytic hydrogenation |
| 投稿时间：2015-04-12 修订日期：2015-05-21 |
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| 郝志强,于智慧,李忠.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[J].无机化学学报,2015,31(8):1571-1580. |
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