Environmentally Friendly, Co-catalyst-Free Chemical Fixation of CO₂ at Mild Conditions Using Dual-Walled Nitrogen-Rich Three-Dimensional Porous Metal–Organic Frameworks

Abstract

Highly porous, polyhedral metal−organic frameworks (MOFs) of Co(II)/Ni(II), {[M 6 (TATAB) 4 (DABCO) 3 (H 2 O) 3 ]•12DMF• 9H 2 O} n (where M = Co(II) (1)/Ni(II) ( 2), H 3 TATAB = 4,4′,4″-striazine-1,3,5-triyl-tri-p-aminobenzoic acid, and DABCO = 1,4diazabicyclo[2.2.2]octane) have been synthesized solvothermally. Both MOFs 1 and 2 show a 2-fold interpenetrated 3D framework structure composed of dual-walled cages of dimension ∼ 30 Å functionalized with a high density of Lewis acidic Co(II)/Ni(II) metal sites and basic -NHgroups. Interestingly, MOF 1 shows selective adsorption of CO 2 with high heat of adsorption (Q st ) value of 39.7 kJ/mol that is further supported by theoretical studies with computed binding energy (BE) of 41.17 kJ/mol. The presence of the high density of both Lewis acidic and basic sites make MOFs 1/2 ideal candidate materials to carry out co-catalyst-free cycloaddition of CO 2 to epoxides. Consequently, MOFs 1/2 act as excellent recyclable catalysts for cycloaddition of CO 2 to epoxides for high-yield synthesis of cyclic carbonates under co-catalystfree mild conditions of 1 bar of CO 2 . Further, MOF 1 was recycled for five successive cycles without substantial loss in catalytic activity. Herein, rational design of rare examples of 3D polyhedral MOFs composed of Lewis acidic and basic sites exhibiting efficient co-catalyst-free conversion of CO 2 has been demonstrated.

PCN-222(Co) Metal–Organic Framework Nanorods Coated with 2D Metal–Organic Layers for the Catalytic Fixation of CO2 to Cyclic Carbonates

“…Unlike the reported catalysts that have been used under high temperatures, high pressures, or both (see Table S1 for comparison), − the catalytic experiments of PCN-222­(Co)@MTTB for the cycloaddition of CO 2 in this work were carried out under mild reaction conditions (50 °C, 1 atm CO 2 ). The catalytic performance of PCN-222­(Co)@MTTB in the cycloaddition reactions of a series of epoxides and CO 2 to form epoxy carbonate was investigated.…”

Recent Developments in the Design of CdxZn1−xS‐Based Photocatalysts for Sustainable Production of Hydrogen

“…MOF-Based Heterostructures: Metal-organic frameworks (MOFs) attracted tremendous interest in the past few decades due to their high surface areas, tunable pore size, and functionality. [159][160][161] MOFs have shown potential utility as supports for anchoring/stabilizing reactive catalytic materials by providing the exposed surface area. Hence the application of porous MOFs as supports for stabilizing active catalysts has been studied by various research groups.…”

Chemical Fixation of Carbon Dioxide by Heterogeneous Porous Catalysts

“…Recently, Ugale et al [24] . showed the mechanism for the catalytic fixation of CO 2 .…”