关键词: MOF材料, 多级孔, 气体吸附, 分离, 传质速率

Abstract:

Metal-organic framework (MOF), which has the advantages of high specific surface area, abundant porosity and adjustable pore size, has received attention from many scholars and is considered as an ideal adsorbent for adsorption and separation. However, in practical applications, most microporous MOF materials are severely limited in their intrinsic mass transfer rates during adsorption, and methods for constructing hierarchically pores are not universally applicable. In this paper, the methods for constructing hierarchical pores MOF such as moderator strategy, template strategy and post-processing strategy were introduced. The hierarchically pores materials with both mesopores and macropores were prepared, and the advantages and disadvantages of each method with application scenarios to obtain a universal strategy for constructing hierarchical pores MOF with adjustable pore size under relatively mild conditions were evaluated. To address the application of hierarchically porous MOF materials in the field of gas adsorption and separation, this paper focused on the case of constructing hierarchical pores MOF to enhance the adsorption of CO₂ gas. It was found that the construction of hierarchically porous increased the pore size, improved the specific surface area of MOF, and provided additional pore channels to enhance the adsorption capacity and mass transfer rate of gas molecules. The results showed that the hierarchically pores MOF had excellent performance in gas adsorption and separation. Finally, the problems of hierarchical pores MOF synthesis and application were discussed, and the challenges faced by hierarchical pores MOF such as green reproducibility of the synthesis process were prospected.

Key words: metal-organic framework, hierarchically pores, gas adsorption, separation, mass transfer rate