Chinese Journal of Applied Chemistry ›› 2020, Vol. 37 ›› Issue (6): 635-641.DOI: 10.11944/j.issn.1000-0518.2020.06.190338

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Effects of Modified HZSM-5 Zeolite Molecular Sieve on the Nitration of Toluene with Dinitrogen Pentoxide

HONG Zhonga,LÜ Zaoshenga*(),CHENG Guangbinb   

  1. aSchool of Chemical Engineering and Technology,Wuhan University of Science And Technology,Wuhan 430080,China
    bSchool of Chemical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China
  • Received:2019-12-16 Accepted:2020-04-17 Published:2020-06-01 Online:2020-06-08
  • Contact: LÜ Zaosheng

Abstract:

Nitrous pentoxide, a new type of green nitrating agent, can replace the traditional highly polluting mixed acid. However, the conversion of direct nitrification by N2O5 is low. In this paper, three methods were used to modify HZSM-5 zeolite molecular sieve. Then, the catalyst was used to nitrate toluene with N2O5, and pyridine Fourier-transform infrared (FT-IR) and X-ray diffraction (XRD) were used for characterization. Experimental results show that the yield of mononitrotoluene is significantly improved after the introduction of the catalyst. Among them, the modification effect of the impregnation method is superior to the ion exchange method. Compared to the unmodified (45.2%), the yield increases by 22.5%; After 5 different concentrations of NaOH modification, it is found that the best modification concentration is 0.2 mol/L, and the nitrification yield reaches 58.5%.

Key words: dinitrogen pentoxide, HZSM-5, nitrotoluene, nitryl cation