In Situ Generation and Stabilization of Accessible Cu/Cu₂O Heterojunctions inside Organic Frameworks for Highly Efficient Catalysis

Abstract

Heterostructural metal/metal oxides are the very promising substituents of noble-metal catalysts;h owever, generation and further stabilization of accessible metal/metal oxide heterojunctions are very difficult. As trategy to encapsulate and stabilizeCu/Cu 2 Onanojunctions in porous organic frameworks in situ is developed by tuning the acrylate contents in copper-based metal-organic frameworks (Cu-MOFs) and the pyrolytic conditions.T he acrylate groups play important roles on improvingt he polymerization degree of organic frameworks and generating and stabilizing highly dispersed and accessible Cu/Cu 2 Oh eteronanojunctions.A saresult, pyrolysis of the MOF ZJU-199, consisting of three acrylates per ligand, generates abundant heterostructural Cu/Cu 2 O discrete domains inside porous organic matrices at 350 8 8C, demonstrating excellent catalytic properties in liquid-phase hydrogenation of furfural into furfuryl alcohol, whicha re muchs uperior to the non-noble metal-based catalysts. Results and DiscussionTheC u-MOF ZJU-199 (ZJU = Zhejiang University) is built from [Cu 2 (COO) 4 ]p addle-wheel secondary building Angewandte Chemie Research Articles Figure 6. Kinetic studies of FAL hydrogenation over ZJU-199-350 catalyst:a )reaction rates of ZJU-199-350 at different temperatures (inset:A rrheniusp lot for the FAL hydrogenation). Reaction conditions: 2.5 mmol FAL, 5mLi sopropanol, 25 mmol catalyst, 1MPa H 2 ,100-130 8 8C, 2h.b)The recyclability of ZJU-199-350 for the hydrogenation of FAL. Reaction conditions: 1.0 mmol FAL, 25 mmol catalyst, 2mL isopropanol, 1MPa H 2 ,130 8 8C, 3h.

Incorporation of Active Metal Species in Crystalline Porous Materials for Highly Efficient Synergetic Catalysis

“…In this regard, to generate accessible metal/metal oxide heteroparticles inside MOF materials seems to provide a new and unique perspective in this field. [26,[111][112][113] However, it is very difficult to construct and stabilize these well-defined metal/metal oxide heteroparticles. In 2018, Li et al subtly constructed robust NiCo/Fe 3 O 4 heteroparticles within MOF-74 by a controlled partial pyrolysis strategy (Figure 9a-h).…”

“…As such, through being controlled thermal treatment, the highly active heteroparticles were formed instead of conventional metal oxides within MOF- 74 9i). [112] The phase compositions and particle sizes of encapsulated Cu/Cu 2 O nanojunctions can be successfully regulated through tuning the pyrolytic conditions and acrylate contents in CuMOFs. In this work, CuMOFs with different functionalities of organic linkers including HKUST-1, ZJU-35, ZJU36-350, and ZJU-199 were used as precursors to generate abundant Cu/Cu 2 O heterostructures.…”

“…o) The recyclability of ZJU-199-350 for the hydrogenation of FAL. Reproduced with permission [112]. Copyright 2020, Wiley-VCH.…”

Enhanced stability of highly-dispersed copper catalyst supported by hierarchically porous carbon for long term selective hydrogenation

“…Since Pd/Cz-MOF-253 prepared by Huang et al [40] was first applied as solid-based catalysts for a one-pot stepwise tandem reaction of Knoevenagel condensation and subsequent hydrogenation in 2017, much attention now has gradually paid on the application of MOFs-derived catalysts in heterogeneous catalysis. The recent study has also report [41] that highly dispersed and accessible Cu/Cu2O heterojunctions inside porous organic matrices through pyrolysis of copper-based MOFs (i.e., ZJU-199), demonstrating excellent catalytic properties in liquid-phase hydrogenation of furfural into furfuryl alcohol.…”

A metal–organic framework/polymer derived catalyst containing single-atom nickel species for electrocatalysis

“…First, many MOFs are constructed by carbon-based ligands with oxygen-coordination sites, and most of the oxygen naturally exits the structure during pyrolysis in the form of CO 2 . 20 This, combined with very low densities of other types of potential metal-coordinating species, such as nitrogen, limits accessible lone pairs on the ligand backbone. As such, many MOF structures have limited capacity to inhibit metal aggregation during pyrolysis.…”