A new approach to enhancing the CO₂ capture performance of defective UiO-66 via post-synthetic defect exchange

Abstract

The effect of post-synthetic incorporation of functional monocarboxylates at defective sites of UiO-66 is systematically investigated, observing enhanced CO2 capture performance.

Band gap modulation in zirconium-based metal–organic frameworks by defect engineering

“…In order to prove that the produced CO effectively derived from CO 2 , we performed a control experiment using FA_mod-2ABA as the catalyst and 13 CO 2 . 13 CO was detected, confirming its origin was from the gaseous stream and not the material and/or traces of solvent ( Figure S61). We note that the performance of FA_mod-2ABA is comparable to that of P25, which is significant, given that recent reports on gas phase CO 2 photoreduction using MOFs typically point towards lower performance of the MOFs compared to P25.…”

“…5,11 The defectcompensating monocarboxylates can be subsequently exchanged post synthesis by soaking the defective MOF in a solution of the desired functional mono-or polycarboxylate, a process known as post-synthetic defect exchange (PSDE) ( Figure S1). 12,13 The resulting MOF is selectively modified at defect sites, with the functional backbone of the newly installed carboxylate exposed within the large cavity associated with a missing-cluster vacancy. Functionalisation of the defective MOF can alternatively be accomplished in one step, by employing the desired functional monocarboxylate as a modulator ( Figure S2).…”

“…On the other hand, a functionalised linker must have well-defined features, in terms of length and geometry, to be incorporated in a non-defective framework, which poses restrictions to the range of accessible functional groups. We have recently explored the potential of PSDE as a method to improve the CO 2 capture performance of defective UiO-66, 13 the prototypical Zr-MOF based on 1,4-benzenedicarboxylic acid (or terephthalic acid, hereafter BDC) as the linker. In the present Please do not adjust margins work, we focus instead on providing proof of concept that the band gap of UiO-66 can be systematically modulated through defect engineering.…”

Strategies to Enhance Carbon Dioxide Capture in Metal‐Organic Frameworks

“…A substantial uptake increase (up to 48 %) was achieved grafting various nitrogencontaining monocarboxylates at defective sites of UiO-66. [40] Post-synthetic defect exchange (PSDE) appears to be a promising approach to enhance the CO 2 uptake performance of zirconium based MOFs.…”

“…The cus in UiO‐66 are introduced by removing the terephthalic acid linker from the network causing a reduced hydrophobicity of the MOF, which is a limitation to further increase the CO 2 adsorption capacity. A substantial uptake increase (up to 48 %) was achieved grafting various nitrogen‐containing monocarboxylates at defective sites of UiO‐66 . Post‐synthetic defect exchange (PSDE) appears to be a promising approach to enhance the CO 2 uptake performance of zirconium based MOFs.…”