Chinese Journal of Catalysis ›› 2019, Vol. 40 ›› Issue (7): 1109-1115.DOI: 10.1016/S1872-2067(18)63198-5

• Articles • Previous Articles    

Preparation of highly dispersed iron species over ZSM-5 with enhanced metal-support interaction through freeze-drying impregnation

Lisong Fan, Dangguo Cheng, Fengqiu Chen, Xiaoli Zhan   

  1. Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2018-10-04 Revised:2018-11-09 Online:2019-07-18 Published:2019-05-24
  • Supported by:

    This work was supported by the National Key R&D Program of China (2016YFA0202900), the National Natural Science Foundation of China (21622606), Zhejiang Provincial Natural Science Foundation of China (LR18B060001), and the Fundamental Research Funds for the Central Universities.

Abstract:

Supported metal catalysts play a vital role in the chemical industry, and the metal-support interaction is an important property of the catalyst. However, in the traditional impregnation method, it is difficult to obtain sufficient metal-support interactions owing to the mobility of the metal precursor during evaporation drying. Here, freeze drying is applied during impregnation instead of evaporation drying for enhancing the metal-support interactions. 57FeZSM-5 was chosen as a representative catalyst. A quantitative analysis was conducted based on Mössbauer spectroscopy. Compared with traditional evaporation-drying catalyst, freeze-drying catalyst has stronger metal-support interactions. In addition, more iron species are confined in the channel and smaller metal sizes and less diversity are obtained. The compositional change is also proved because of the superior performance of the freeze-drying catalyst during N2O decomposition. This method can be extended to other supported metal catalysts prepared through an impregnation method, which can be used to tune the metal-support interactions and metal sizes.

Key words: Iron, ZSM-5 zeolite, Freeze drying, Impregnation, Metal-support interaction, Metal size