Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 911-919.doi: 10.3866/PKU.WHXB201302273

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Phenomenon of Structural Transformation of Ethylenediamine- Oriented Synthesis of Microporous Cobalt Phosphate

LUO Qian-Qian, ZHOU Shi-Dong, REN Yuan, Li Niu, HUANG Zhi-Peng, GUAN Nai-Jia, XIANG Shou-He   

  1. Key Laboratory of Advanced Energy Materials Chemistry, Ministry of Education, Department of Materials Chemistry, Nankai University, Tianjin 300071, P. R. China
  • Received:2013-01-03 Revised:2013-02-27 Published:2013-04-24
  • Supported by:

    The project was supported by the Natural Science Foundation of Tianjin, China (12JCYBJC12700) and National Major Fundamental Research Program of China (973) (2009CB623502).

Abstract:

Microporous cobalt phosphate structures can be synthesized using ethylenediamine as a structure directing agent. During the syntheses of CoPO-en-1, CoPO-en-2, CoPO-en-3, and CoPO-en-4, it was found that they could interconvert during hydrothermal or calcination conditions. CoPO-en-2 and CoPO-en-4 are the crystallization intermediates of CoPO-en-1 and CoPO-en-3, respectively. During hydrothermal synthesis, CoPO-en-2 and CoPO-en-4 could be obtained at lower temperature or higher temperature during the initial crystallization stage. Extended synthesis time at higher temperature the two former structures transform into the two latter. CoPO-en-2, CoPO-en-3, and CoPO-en-4 could also convert to CoPO-en-1 during calcination, and these transformations indicated the sequence of structure stability. During synthesis under hydrothermal conditions, CoPO-en-2, CoPO-en-3, and CoPO-en-4 could convert to CoPO-en-1. During muffle furnace roasting, CoPO-en-2, CoPO-en-3, and CoPO-en-4 could also convert to CoPO-en-1. Different structures in the liquid or solid phases could be transformed into the same structure using different approaches.

Key words: Cobalt phosphate, Ethylenediamine, Structural transformation, Hydrothermal synthesis, Calcination transformation