Coupling Molecular and Nanoparticle Catalysts on Single Metal–Organic Framework Microcrystals for the Tandem Reaction of H₂O₂ Generation and Selective Alkene Oxidation

Abstract

A molecular catalyst, (sal)Mo VI , and a heterogeneous catalyst, either Pd or Au nanoparticles (NPs), were integrated into one UiO-66 MOF microcrystal. The resulting dually functionalized catalysts, Pd@UiO-66-(sal)Mo and Au/UiO-66-(sal)Mo, have been utilized for a one-pot tandem reaction of H 2 O 2 generation and selective liquid-phase alkene oxidation. The NPs serve as catalysts for the production of H 2 O 2 from H 2 and O 2 gases, while the (sal)Mo moieties function as the oxidation catalyst. When the metal NPs are fully encapsulated within the MOF microcrystals, the alkene hydrogenation side reaction is largely suppressed, with a 6-fold decrease in the hydrogenation/oxidation product ratio for 5-bromo-1-cyclooctene favoring the epoxide as the major product. For Au/UiO-66-(sal)Mo, where the two catalysts are in close proximity on the MOF microcrystal, the enhancement in oxidation productivity is increased by 10 times in comparison to the [Au/UiO-66-NH 2 + UiO-66-sal(Mo)] physical mixture of the two singly functionalized MOFs.

A Facile Method for Preparing UiO-66 Encapsulated Ru Catalyst and its Application in Plasma-Assisted CO2 Methanation

“…The utility of UiO-66 as a support for metal catalysts (M/UiO-66, M=Cu, Au, Pd, Pt, Ru, etc.) has been extensively studied by researchers recently [14,15,16,17,18,19]. For example, Milet et al [18] reported Pt/UiO-66 catalysts prepared by the double solvent method: impregnation of the UiO-66 support with the aqueous solution of H 2 PtCl 6 , and then reduction with NaBH 4 solution.…”

Heterogeneous Metal–Organic‐Framework‐Based Biohybrid Catalysts for Cascade Reactions in Organic Solvent

“…In this work, UiO-66-NH2 was chosen as "hard" scaffold owing to its high stability and ready post-functionality. [24] Excess benzoic acid was added during preparing UiO-66-NH2 following reported protocol, [25] because it could not only lead to MOFs with small sizes, [26] but also offer the opportunities for postmodification through ligand exchange. [27] Initially, the assynthesized UiO-66-NH2 was employed for ligand exchange.…”

Functional Macro‐Microporous Metal–Organic Frameworks for Improving the Catalytic Performance

“…However, most of the reported MOFs exhibit catalytic properties restricted to the microprous regime, which is usually limited by molecular diffusion. When the active species are encapsulated inside the MOFs matrixes (such as NPs), the catalytic efficiency usually is low, especially in the multisteps catalytic reaction . In order to enhance the catalytic activity and further expand the applications of MOFs, it is crucial to develop appropriate strategies to regulate the porous structure of MOFs.…”