Facile synthesis of dptz-CuGeF6 at room temperature and its adsorption performance for separation of CO2, CH4 and N2

作者：Shen, Shigen; Xu, Feng; Chen, Xin; Miao, Guang; Li, Zhong; Zhou, Xin^*; Wang, Xun^*

来源：SEPARATION AND PURIFICATION TECHNOLOGY, 2022, 302: 122054.

DOI：10.1016/j.seppur.2022.122054

• Metal-organic frameworks (MOFs)
• Stability
• CO2 separation
• Biomethane purification
• Selectivity

Efficient capture of CO2 from flue gas and removal of CO2 from biomethane by physical adsorption are in great need. Herein, we report the facile synthesis of a new pillared-layer metal-organic frameworks, dptz-CuGeF6 for CO2 separation from the flue gas or the biomethane. The resulting samples were characterized. Structurally, the dptz-CuGeF6 possess double-interpenetrated frameworks formed by two staggered, independent sql sheets, in which the cations Cu2+ are coordinated by four dptz ligands, making the dptz-CuGeF6 exhibit narrow and uniform ultra-micropores of 5.25 A. Its CO2 capacity reached 2.17 mmol/g at 15 kPa and 3.23 mmol/g at 100 kPa separately, and its selectivity of CO2/CH4 (50:50) and CO2/N-2 (15:85) reached as high as 80 and 175.5, respectively. The stability experiments demonstrated the intact structure of dptz-CuGeF6 was retained after exposure in moisture air (RH = 50% or RH = 80%) as well as in several polar solvents. Breakthrough experiments confirmed that CO2/CH4 or CO2/N-2 binary mixture were efficiently separated. Molecule simulation revealed that both F center dot center dot center dot CCO2 and multiple C-H center dot center dot center dot OCO2 interactions in the pores of dptz-CuGeF6 played an important role in enhancing its selectivity of CO2 adsorption. The dptz-CuGeF6 would be promising for CO2 capture and separation from flue gas or biomethane.

• 单位
  佛山科学技术学院