Batch versus Flow Acetalization of Benzaldehyde with HKUST‐1: Diffusion Pathways and Performance Comparison

Abstract

Understanding the poisoning and deactivation pathways of metal–organic frameworks (MOFs) is an essential goal to boost their application as robust and efficient catalysts in chemical transformations relevant to industrial processes. Herein, the acetalization reaction of benzaldehyde with methanol was investigated by using [Cu3(BTC)2] (BTC=1,3,5‐benzenetricarboxylate) as a catalyst. The reaction was performed under batch and continuous flow conditions, and the conversion of benzaldehyde into 1,1‐dimethoxytoluene proceeded efficiently in the presence of a modest amount of water. Nevertheless, a drastic reduction in the catalytic activity was observed after recycling the MOF for repetitive batch experiments and after prolonged continuous flow tests. Pore clogging of the MOF and partial crystal‐structure modifications, gathered from XRD and pore analyses, suggested grinding the catalyst prior to application; the ground catalyst showed a considerable enhancement in catalytic performance.

Design and Characterization of MOF s (Metal–Organic Frameworks) for Innovative Applications

“…One of the most famous MOFs showing Lewis acidity is, without doubt, HKUST-1 (101)(102)(103)(104)(105)(106). Recent examples showing the effect of these two approaches in the field of light harvesting, (113) energy storage (114) and conductive properties (115), will be briefly reviewed in this Section, while hydrogen gas storage and carbon dioxide sequestration have been already discussed in Section 3.1.…”

Luminescence properties of mixed-ligand MOFs containing fluorene scaffolds functionalized with isonicotinoyl arms

“…5 The crystallinity of MOFs and the knowledge of their precise crystalline structure enable the design of new architectures and the development of new functional materials that make MOFs highly attractive in several applications, such as gas storage and separation, [6][7][8][9][10] guest-inclusion, [11][12][13][14][15] development of electronic materials, 16,17 food 18 and environmental 19 control and heterogeneous catalysis. [20][21][22][23] Among the physical properties that can be imparted to MOFs, luminescence covers a prominent role in the development of responsive crystalline materials. Indeed, luminescent MOFs (LMOFs), first reported in 2002, 24 are well documented in the literature as sensors [25][26][27] or as light emitters [28][29][30][31][32] or for biological applications.…”

Guest Molecules Play Tug of War in a Breathing MOF: The Stepwise Monitoring of an Elastic Framework Deformation via SC-SC Transformations

“…In fact, the most popular applications of MOFs are related to gas adsorption, 15 guest inclusion, 16−18 and heterogeneous catalysis. 19,20 Hence, knowing how the framework changes in response to the variation of the included solvent is of paramount importance for developing MOF applications. 21,22 Noticeably, it is well-known that such transformations can be reversible, and in these cases the pristine structure can be regained by exposing the activated crystals back to the solvent, giving rise to the so-called "breathing of the MOF".…”