Chinese Journal of Catalysis ›› 2015, Vol. 36 ›› Issue (11): 1949-1956.DOI: 10.1016/S1872-2067(15)60945-7

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Amine-grafted on lanthanide metal-organic frameworks: Three solid base catalysts for Knoevenagel condensation reaction

Yanwei Rena, Jiaxian Lua, Ou Jiangb, Xiaofei Chenga, Jun Chenb   

  1. a School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, Guangdong, China;
    b Guangdong Winner Functional Materials Co., Ltd, Foshan 528521, Guangdong, China
  • Received:2015-05-29 Revised:2015-07-03 Online:2015-11-02 Published:2015-11-02
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21372087).

Abstract:

A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er(btc)(ED)0.75(H2O)0.25 (2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine), Er(btc)(PP)0.55(H2O)0.45 (3, PP = piperazine), and Er(btc)(DABCO)0.15(H2O)0.85 (4, DABCO = 1,4- diazabicyclo[2.2.2]octane), by grafting three different diamines onto the coordinatively unsaturated Er(III) ions into the channels of the desolvated lanthanide metal-organic framework (Er(btc)). The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4 for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.

Key words: Lanthanide metal-organic framework, Post-synthetic modification, Solid base catalyst, Knoevenagel condensation reaction, Size-selective catalysis