Acta Chimica Sinica ›› 2020, Vol. 78 ›› Issue (1): 63-68.DOI: 10.6023/A19110397 Previous Articles     Next Articles

Article

一种沿骨架进行质子传导的二维共价有机框架的合成

王志涛a,b, 李辉a, 颜士臣a, 方千荣a   

  1. a 吉林大学化学学院 无机合成与制备化学国家重点实验室 长春 130012;
    b 通化师范学院化学学院 通化 134002
  • 收稿日期:2019-11-07 出版日期:2020-01-15 发布日期:2020-01-17
  • 通讯作者: 方千荣 E-mail:qrfang@jlu.edu.cn
  • 基金资助:
    项目受国家自然科学基金(No.21571079)资助.

Synthesis of a Two-dimensional Covalent Organic Framework with the Ability of Conducting Proton along Skeleton

Wang Zhitaoa,b, Li Huia, Yan Shichena, Fang Qianronga   

  1. a State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, School of Chemistry, Jilin University, Changchun 130012, China;
    b School of Chemistry, Tonghua Normal College, Tonghua 134002, China
  • Received:2019-11-07 Online:2020-01-15 Published:2020-01-17
  • Supported by:
    Project supported by the National Natural Science Foundation of China (No. 21571079).

Nitrogen heterocyclic compound like imidazole and triazole are often loaded in porous material for proton conduction. Inspired by this, we employ 5,5'-diamino-3,3'-bis(1H-1,2,4-triazole) (BTDA) containing triazole fragments in the structure as the construction unit to react with 2,4,6-triformylphloroglucinol (TFP) through Schiff-base condensation reaction to synthesize a novel two-dimensional covalent organic framework named TFP-BTDA-COF. The theoretical results were simulated using the Accelrys Material Studios 7.0 software package and compared with the powder X-ray diffraction (PXRD) test data to confirm the crystal structure of TFP-BTDA-COF. The porosity and pore structure of TFP-BTDA-COF were characterized by N2 adsorption-desorption at 77 K. The condensation reaction was confirmed by Fourier transform infrared spectroscopy (FTIR). Due to the π-π accumulation of the 2D-COF, the N-H bond of the triazole in BTDA connecting unit is periodically and regularly arranged on each layer of the COF to form an ordered array. Under certain humidity conditions, the protons can be transmitted along the array in the one-dimensional pore channel by the intermediary of water molecules. Therefore, the TFP-BTDA-COF has the ability to conduct proton through the skeleton. The proton conductivity of TFP-BTDA-COF is tested by the AC impedance method. The results show that the proton conductivity of the material is gradually enhanced with the increase of the ambient humidity, and the maximum value is 1.4×10-3 S·cm-1 at 98% relative humidity. The PXRD of TFP-BTDA-COF in boiling water for 2 h and after 12 h AC impedance test were compared with the original experimental value to evaluate its tolerance under the working conditions of the proton membrane fuel cell. The PXRD diffraction peak intensity did not change obviously compared with that of the original experimental value. The thermogravimetric analysis results show that the thermal stability of TFP-BTDA-COF can reach high to 400℃. The above evidence proves that it has the potential to be used in proton membrane fuel cells.

Key words: covalent organic framework, proton conduction, crystal structure, AC impedance