Two Stable Sodalite-Cage-Based MOFs for Highly Gas Selective Capture and Conversion in Cycloaddition Reaction

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) with Lewis acid-base sites are promising for heterogeneous catalysis.
• Reticular chemistry principles enable the design of MOFs with specific topologies and functionalities.

Purpose of the Study:

• To synthesize and characterize novel zeolitic metal-organic frameworks (ZMOFs) with sod topology.
• To investigate the gas capture, selective separation, and catalytic CO2 conversion capabilities of the synthesized ZMOFs.

Main Methods:

• Synthesis of PCP-33(Mn) and PCP-34(Mn) ZMOFs using Mn(II) with pyridine N-rich linkers H3TBA and H2TZI.
• Characterization of ZMOF structures, including micropores, cages, and active sites.
• Evaluation of gas adsorption (C2H2, CO2) and separation (C2H2/CH4, CO2/CH4) performance.
• Assessment of catalytic activity for CO2 fixation with epoxides and recyclability.

Main Results:

• PCP-33(Mn) and PCP-34(Mn) ZMOFs with sod topology and hierarchical pores were successfully synthesized.
• The ZMOFs demonstrated high surface area and small pore windows, leading to outstanding gas capture (C2H2: 131.8 cm3 g-1, CO2: 77.9 cm3 g-1 at 273 K).
• Excellent selective gas separation was achieved (C2H2/CH4: 226.2, CO2/CH4: 50.3 at 298 K).
• The ZMOFs served as efficient, recyclable catalysts for metal/solvent-free CO2 conversion with epoxides.

Conclusions:

• The designed ZMOFs possess unique structural features for enhanced gas interactions.
• These ZMOFs show significant potential for industrial applications in gas storage, separation, and CO2 utilization.
• The recyclability and retained activity highlight the stability and robustness of these novel materials.