纳米-微米铁修饰的维氏体氨合成催化剂（英文）

发布时间：2018-05-05 15:56

  本文选题：氨合成 + 固相反应　； 参考：《分子催化》2017年03期

【摘要】：我们以商业预还原的维氏体(Fe_(1-x)O)氨合成催化剂为载体,采用Fe(NO)_3·9H_2O和H_2C_2O_4·2H_2O进行原位室温固相反应制备纳米铁或微米铁修饰的铁基氨合成催化剂,并通过XRD、SEM、TG-DTG、H_2-TPR等进行了表征.结果表明:Fe(NO)_3·9H_2O和H_2C_2O_4·2H_2O室温固相反应完全生成产物Fe_2(C_2O_4)_3·5H_2O,且产物分散于载体维氏体催化剂表面.通过纳米铁-微米铁的修饰,催化剂的氨合成活性有很大提高且稳定性好.催化剂活性随着Fe负载量的增加先增加后降低,负载量5%时催化活性最好,反应器出口氨浓由450℃(12.4%)、425℃(11.0%)、400℃(9.4%)分别提升至450℃(15.6%)、425℃(14.8%)、400℃(13%).通过一步简单的修饰,维氏体催化剂的氨合成活性提高约25%~38%.由于焙烧和还原,生成的Fe_(1-x)O或铁粒子与铁催化剂表面发生强相互作用,因此,反应过程中纳米铁或微米铁粒子能稳定存在,催化剂有较高的稳定性.
[Abstract]:In situ solid state reaction at room temperature with Fe(NO)_3 9H_2O and H_2C_2O_4 2H_2O was used to prepare iron nanoparticles or iron modified iron based ammonia synthesis catalysts. The catalysts were characterized by XRDX SEMU TG-DTGN H2-TPR and so on. The results showed that the product Fe_2(C_2O_4)_3 _ 5H _ 2O was completely formed by solid state reaction of Fe_2(C_2O_4)_3 _ 5H _ 2O with H_2C_2O_4 2H_2O at room temperature, and the product was dispersed on the surface of the supported Vickers catalyst. The ammonia synthesis activity of the catalyst is greatly improved and the stability is good through the modification of nanometer iron-micron iron. The catalytic activity increased first and then decreased with the increase of the amount of Fe loading. The catalytic activity was the best when the loading amount was 5. The ammonia concentration at the outlet of the reactor was increased from 450 鈩，

本文编号：1848316