Metal-Organic Frameworks for Separation of C₂ Hydrocarbons: From Molecular Design to Industrial Applications

The separation of C₂ hydrocarbons (C₂H₂, C₂H₄, and C₂H₆) for high-demanding pure feedstocks, especially polymer-grade C₂H₄, represents the cornerstone of modern chemical industry. However, traditional distillation technology is energy consumptive, thus propels the search for greener and more efficient alternatives. Metal-organic frameworks (MOFs) are crystalline porous materials with structural tailorability. Benefiting from regulable pore channels, modifiable surface chemistry and special stimulus-triggered flexibility, they display outstanding prospects for adsorptive separation of C₂ hydrocarbons. This review provides a systematic overview of recent research progress in MOF materials applied to C₂ hydrocarbon separation, including one-step purification of C₂H₄, separation of C₂H₆/C₂H₄, and recovery of C₂H₄. It focuses on molecular design strategies for MOFs such as pore size engineering, electrostatic potential modulation, gating effects controlled by framework flexibility, and heterometallic synergy. The role of dynamic breakthrough experiments and theoretical calculations in elucidating separation mechanisms are also examined. Furthermore, we discuss critical challenges toward industrialization, such as material cost, large-scale synthesis, and long-term industrial stability. Finally, future perspective on advancing MOF materials for C₂ hydrocarbon separation from laboratory-scale research to practical industrial applications, are discussed in detail, which offers an essential reference for the development of the next-generation technologies for gas separation.