Robust {Pb₁₀}-Cluster-Based Metal-Organic Framework for Capturing and Converting CO₂ into Cyclic Carbonates under...

Developing a highly active catalyst that can efficiently capture and convert carbon dioxide (CO₂) into high-value-added energy materials remains a severe challenge, which inspires us to explore effective metal-organic frameworks (MOFs) with high chemical stability and high-density active sites. Herein, we report a robust 3D lead(II)-organic framework of {(Me₂NH₂)₂[Pb₅(PTTPA)₂(H₂O)₃]·2DMF·3H₂O} (NUC-111) with unreported [Pb₁₀(COO)₂₂(H₂O)₆] clusters (abbreviated as {Pb₁₀}) as nodes (H₆PTTPA = 4,4',4″-(pyridine-2,4,6-triyl)triisophthalic acid). After thermal activation, NUC-111a is functionalized by the multifarious symbiotic acid-base active sites of open Pb²⁺ sites and uncoordinated pyridine groups on the inner surface of the void volume. Gas adsorption tests confirm that NUC-111a displays a higher separation performance for mixed gases of f CO₂ and CH₄ with the selectivity of CO₂/CH₄ at 273 K and 101 kPa being 31 (1:99, v/v), 23 (15:85, v/v), and 8 (50:50, v/v), respectively. When the temperature rises to 298 K, the selectivity of CO₂/CH₄ at 101 kPa is 26 (1:99, v/v), 22 (15:85, v/v), and 11 (50:50, v/v). Moreover, activated NUC-111a exhibited excellent catalytic performance, stability, and recyclability for the cycloaddition of CO₂ with epoxides under mild conditions. Hence, this work provides valuable insight into designing MOFs with multifunctionality for CO₂ capture, separation, and conversion.