Relationship Between Structure and Separation Property

Separation processes represent a significant proportion of global energy consumption. The distillation is responsible for 90–95% of all separations in the chemical and petroleum refining industries. In particular, different molecules of industrial interest (olefins, paraffins, alkanes, rare gases, etc.), due to similarities in physicochemical properties of mixed molecules, are being extracted using (cryogenic) distillation. Additionally, other special separations such as hydrogen isotope and enantiomers are also intensive challenges in industry. Focusing on the size and shape selectivity, guest–framework interaction, polarizability, even chirality, etc., the application of metal–organic frameworks (MOFs) to separation technology is considered to be very promising to overcome the shortcomings of high energy consumption of traditional separation technology. Furthermore, the concise structural information of MOFs endows them to be an excellent platform for studying the relationship between the structure and the separation. In this chapter, we will introduce CO2 capture and separation, separation of hydrocarbons, separation of noble gases, separation of hydrogen isotopes, and enantioselective separation based on MOFs. Meanwhile, the relationship between structure and separation during these processes will be discussed in detail.