Available Technologies

Background

Metal-organic frameworks (MOFs), porous materials with numerous pores, have been attracting attention as promising materials for CO2 adsorption. In particular, structurally flexible MOFs having flexible frameworks exhibit excellent CO2 adsorption and separation performance due to their unique adsorption behavior accomplished by volume expansion (gate adsorption). However, it has been practically challenging to mold such structurally flexible MOFs as their shapes as well as their gas adsorption behavior need to be maintained both before and after their volume expansion.

Description and Advantages

Researchers at Kyoto University have found that freeze-drying structurally flexible MOFs during the molding process can suppress pulverization caused by volume expansion even when the amount of used binder was reduced. This freeze-drying method enables the molding of structurally flexible MOFs with excellent CO2 adsorption and separation performance. Furthermore, it is expected to be applied to mold various structurally flexible MOFs with enhanced adsorption and separation performance for gases other than CO2.

•  Excellent adsorption characteristics and suppressed pulverization

Because MOF bodies molded by the novel method using freeze-drying are not pulverized even when only a small amount of binder is used, they retain adsorption performance similar to that in powder form. As shown in Fig. 1, samples fabricated by the novel method were not pulverized even after multiple adsorption and desorption cycles, while maintaining high adsorption performance as shown in Fig. 2.