Supported Metal Nanoparticles in Metal‐Organic Monoliths for Assembly of a Catalytic Microfluidic Reactor

Abstract

A novel strategy has been developed to fabricate an Au@CrADC (ADC=5‐aminobenzene‐1,3‐dicarboxylate) metal‐organic monolithic capillary in microfluidic reactors. Monolithic Cr3+‐based metal‐organic gel (MOG) as catalyst support is synthesized inside fused‐silica capillary employing a two‐step procedure including surface modification of carboxyl group to provide anchoring sites and subsequent MOG formation. Subsequently, Au nanoparticles are in situ immobilized in the monolithic MOG support as active catalysts. The resulting Au@CrADC monolithic capillary is used to assemble a catalytic microfluidic reactor. The catalytic activity of the Au@CrADC reactor is probed by using the oxidative alkyne coupling reaction to synthesize 1,3‐diynes. The catalytic microfluidic reactor demonstrates significantly enhanced catalytic activity in comparison with the corresponding reactions under batch conditions. Additionally, the microfluidic reactor shows high stability with no significant catalytic deactivation during repeated uses.

Hierarchical porous metal–organic gels and derived materials: from fundamentals to potential applications

“…15e) was realized by fabricating a monolithic capillary with a Cr 3+ based gel as a catalyst, Cr 2 (adc) 3 gel (adc 2− = 5-amino-1,3-benzenedicarboxylate) containing Au NPs. 298 The synthesized Au@Cr 2 (adc) 3 capillary with 2 mmol% of catalyst and 0.003 mmol of Au NPs showed a product yield of 95% over a time period of 200 min. Due to the close packing of Au NPs inside the Cr 2 (adc) 3 gel, the reactor showed high stability for five subsequent cycles without any Au NPs leaching and maintaining 94% yield.…”

“…The potential of MOGs as catalysts or catalyst supports is not only limited to the above mentioned reactions but also has found its use for various other reactions, including condensation, dimerization, coupling and transesterification reactions. 297,298,307,308 For instance, Lee et al constructed a metal-organic xerogel from a cyclohexane-based tripyridine linker and Cd 2+ ions as a Knoevenagel condensation catalyst. 307 By taking the Cd 2+ based xerogel as a base catalyst for benzaldehyde condensation in the presence of nitrile compounds with different activity like cyano-acetic acid tert-butyl ester, malononitrile and ethyl cyanoacetate, a good product yields of 75%, 80% and 73%, respectively, were achieved.…”

“…(e) Representation of the setup of a microfluidic reactor based on a monolithic capillary alkyne coupling. Reproduced with permission 298. Copyright 2021, John Wiley & Sons, Inc.…”

Diverse Supports for Immobilization of Catalysts in Continuous Flow Reactors

“…[70][71][72] As a type of porous material, MOGs possess meso-/macropores for mass transfer and micropores for the immobilization of catalysts. [73] Recently, Zhang and coworkers [74] firstly introduced MOGs into flow reactors as the monolithic support to incorporate catalysts for flow reactions. The fused-silica capillary was functionalized with carboxyl groups for the attachment with the gel monolith, followed by the addition of chromium nitrate [Cr(NO 3 ) 3 ] and 5-aminobenzene-1,3-dicarboxylic acid (H 2 ADC) as precursors to develop the CrADC gel.…”

Crystal-to-crystal investigations of highly thermally stable three-dimensional coordination polymer based on sodium(I) ions and 4,4’-stilbenedicarboxylic acid

“…In addition, the synthesis of CPs is an easily scalable process, and the characterization of the obtained crystal compounds is simple using X-ray diffraction methods (Lee et al, 2021;Teo et al, 2021). Such properties of these compounds make them a very attractive materials of potential applications in various fields, including storage and separation (Fan et al, 2021;Li et al 2022), drug delivery (Mallakpour et al, 2022;Cao et al, 2020), catalysis (Chen et al, 2021;Yang et al, 2021), proton conduction (Luo et al, 2019), and optical materials (Fu et al, 2020). Porous coordination polymers are also investigated as an ion exchangers and lightning harvesting materials (Hu et al, 2021;Fan et al, 2022).…”