SCUT scientists resolve key issue in developing porous materials



Researchers of SCUT have created the world’s first ordered macro-microporous metal-organic framework single crystal, a novel porous material that is expected to show great promises for numerous frontiers such as catalysts, electrode materials, photochemistry, and drug delivery.
The scientific work was last Friday highlighted on the Science magazine, listing Associate Professor Shen Kui as the first author and Professor Li Yingwei as a co-corresponding author, both of whom are faculty members of SCUT’s School of Chemistry and Chemical Engineering.
When speaking of materials with porous structures, it often reminds people of common things such as corals, sponges and bottle corks. Uses of such kind of materials can be much more extensive, only if scientists are able to modify and manage their pore sizes and arrays.
Therefore, the synthesis of materials with highly ordered, meso- or macro-porous, and crystalline structure remains a great challenge for scientific research, particularly with respect to the difficulty of enlarging the pores of metal-organic frameworks (MOFs), an advanced type of materials that can be widely applied in gas absorption, gas separation, sensing, or catalysis.
Currently, diameters of pores in most of the known MOF materials are limited within two nanometers, which strictly restricts their application with large-size compounds. Some effective approaches have been developed to build larger pores within MOFs, but meso-pores built upon these strategies often suffer rapid collapse due to disordered or polycrystalline structures.
Now a solution to this puzzle is provided. Shen Kui and Li Yingwei’s team has successfully constructed highly oriented and ordered macro-pores within MOF single crystals, opening up the area of three-dimensional–ordered materials containing both macro- and micro-pores in single-crystalline form.
The team ordered arrays of microcrystals of the ZIF-8 MOF, in which zinc ions are bridged by 2-methylimidazole linkers, inside a porous polystyrene template. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional ZIF-8 materials.
These work presents the world’s first example of assembling highly oriented and ordered macro-porous system into single-crystalline microporous materials. It was highly valued by peer-reviewers of the Science magazine, who recognized the research as an “elegant strategy” of synthesis, and a presentation of “a beautiful chemistry”.
It is expected that the strategy could also be extended to the development of other single-crystalline macro/microporous materials that show great promises for numerous frontiers such as catalysts, electrode materials, photochemistry, and drug delivery.
Besides team members of SCUT, researchers who completed this work together included Professor Chen Banglin at the University of Texas at San Antonio, who is also a co-corresponding author, as well as Professor Han Yu at the King Abdullah University of Science and Technology and Professor Rafael Luque at the University of Córdoba.

Source from the School of Chemistry of Chemical Engineering
Translated by Shen Kui and Xu Peimu
Edited by Xu Peimu and Cheng Yu