The separation and purification of light hydrocarbons (LHs) mixtures is one of the most significantly important but energy demanding processes in the petrochemical industry. As an alternative technology to energy intensive traditional separation methods, such as distillation, absorption, extraction, etc., adsorptive separation using selective solid adsorbents could potentially not only lower energy cost but also offer higher efficiency. The need to develop solid materials for the efficiently selective adsorption of LHs molecules, under mild conditions, is therefore of paramount importance and urgency. Metal–organic frameworks (MOFs), emerging as a relatively new class of porous organic–inorganic hybrid materials, have shown promise for addressing this challenging task due to their unparalleled features. Herein, recent advances of using MOFs as separating agents for the separation and purification of LHs, including the purification of CH4, and the separations of alkynes/alkenes, alkanes/alkenes, C5–C6–C7 normal/isoalkanes, and C8 alkylaromatics, are summarized. The relationships among the structural and compositional features of the newly synthesized MOF materials and their separation properties and mechanisms are highlighted. Finally, the existing challenges and possible research directions related to the further exploration of porous MOFs in this very active field are also discussed.

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Selective hydrogenation of CO2 to methanol is a “two birds, one stone” technology to mitigate the greenhouse effect and solve the energy demand–supply deficit. Cu-based catalysts can effectively catalyze this reaction but suffer from low catalytic stability caused by the sintering of Cu species. Here, we report a series of zeolite-fixed catalysts Cu/ZnO x (Y)@Na-ZSM-5 (Y is the mass ratios of Cu/Zn in the catalysts) with core–shell structures to overcome this issue and strengthen the transformation. Fascinatingly, in this work, we first employed bimetallic metal–organic framework, CuZn-HKUST-1, nanoparticles (NPs) as a sacrificial agent to introduce ultrasmall Cu/ZnO x NPs (∼2 nm) into the crystalline particles of the Na-ZSM-5 zeolite via a hydrothermal synthesis method. The catalytic results showed that the optimized zeolite-encapsulated Cu/ZnO x (1.38)@Na-ZSM-5 catalyst exhibited the space time yield of methanol (STYMeOH) of 44.88 gMeOH·gCu –1·h–1, much more efficient than the supported Cu/ZnO x /Na-ZSM-5 catalyst (13.32 gMeOH·gCu –1·h–1) and industrial Cu/ZnO/Al2O3 catalyst (8.46 gMeOH·gCu –1·h–1) under identical conditions. Multiple studies demonstrated that the confinement in the zeolite formwork affords an intimate surrounding for the active phase to create synergies and avoid the separation of Cu–ZnO x interfaces, which results in an improved performance. More importantly, in the long-term test, the Cu/ZnO x (1.38)@Na-ZSM-5 catalyst exhibited constant STYMeOH with superior durability benefitted from its fixed structure. The current findings demonstrate the importance of confinement effects in designing highly efficient and stable methanol synthesis catalysts.

Solid–liquid separation of similarly sized organic molecules utilizing sorbents offers the potential for new energy-efficient approaches to a number of important industrial separations such as xylenes (C8) separations.