Interwrapping Distinct Metal-Organic Frameworks in Dual-MOFs for the Creation of Unique Composite Catalysts

Abstract

Incorporating metal nanoparticles (MNPs) inside metal-organic frameworks (MOFs) demonstrates superior catalytic properties in numerous reactions; however, the size and distribution of MNPs could not be well controlled, resulting in low product selectivity in catalysis by undergoing different catalytic reaction pathways. We report herein a facile strategy for integrating lattice-mismatched MOFs together to fabricate homogeneously distributed “dual-MOFs,” which are the ideal precursors for the preparation of MNPs@MOFs with unique catalytic properties. As a proof of concept, we successfully synthesize a dual-MOF HKUST-1/ZIF-8 for in situ creation of redox-active Cu NPs inside hierarchical porous ZIF-8 under controlled pyrolytic conditions. Combining the advantages of size-tunable Cu NPs in the molecular sieving matrix of ZIF-8, Cu@ZIF-8 demonstrates high activity and selectivity for transformation of alkynes into alkenes without overhydrogenation, which surpasses most of the catalysts in the literature. Therefore, this work paves a new pathway for developing highly efficient and selective heterogeneous catalysts to produce highly value-added chemicals.

Precise Design and Deliberate Tuning of Turn-On Fluorescence in Tetraphenylpyrazine-Based Metal−Organic Frameworks

“…Precise design and prediction of MOFs with different topologies can be easily achieved through reticular chemistry methods [20][21][22][23][24]. MOFs are built from ligands and metal ions/clusters, which means that the structure of MOFs can be adjusted by implementing a molecular building block (MBB) approach to obtain targeted polynuclear rare earth (RE) metal clusters, and tuning the geometry, length, and functional groups of the ligands [25][26][27][28][29][30]. In other words, the design and prediction of MOFs and topologies can be reached by changing RE metal clusters and ligands with well-defined geometries [31][32][33].…”

Poly(trimethylene carbonate)‐b‐poly(ethylene glycol) diblock copolymer micelles for hydrophobic drug delivery: The effect of hydrophilic/hydrophobic segment length on micellar properties and drug loading

“…Figure S1b shows the FT‐IR spectra of TMC, PEG, and PTMC‐PEG. The vibration peak of 1730 cm −1 is assigned to CO‐stretching in the TMC monomer structure, 37 and the peak of 1110 cm −1 to the stretching vibration of CO group 38 . Compared to TMC spectra, the stretching vibration peak of 2880 cm −1 is assigned to CH 2  group of PEG repeating unit, and the stretching vibration peak of 1110 cm −1 is to CO group 39 .…”

“…The vibration peak of 1730 cm À1 is assigned to C O-stretching in the TMC monomer structure, 37 and the peak of 1110 cm À1 to the stretching vibration of C O group. 38 Compared to TMC spectra, the stretching vibration peak of 2880 cm À1 is assigned to CH 2 group of PEG repeating unit, and the stretching vibration peak of 1110 cm À1 is to C O group. 39 All these data prove that PTMC 2400 -PEG 2000 copolymer was successfully synthesized.…”

Transformation of metal–organic frameworks with retained networks

“…95,96 Various MOFs could be incorporated together using one as the template or intertemplating, resulting in more complicated chemical compositions and/or sophisticated morphologies. [97][98][99] As well as coating of different materials on the surfaces of MOFs, MOFs' pores can also confine and guide the transformation of guest species. It is possible, for example, to utilize the confinement of pores and channels in MOFs to encapsulate the nanoentities and control the polymerization through the utility of the MOFdefined geometries as templates, where the pore dimensionality plays a vital role in polymer tailoring.…”

“…4). 99 Based on the distinct acid and alkali stability of two MOFs, ZIF-8 and HKUST-1, in the composite, they could be individually removed via chemical etching, resulting in hierarchical individual MOFs. Additionally, the different thermal stability of the two MOFs allowed HKUST-1 to be easily pyrolyzed, while the framework skeleton of ZIF-8 remained intact under appropriate pyrolytic conditions.…”