Enhancing Zeolite Performance by Catalyst Shaping in a Mesoscale Continuous‐Flow Diels–Alder Process

Abstract

In contrast to most lab‐scale batch procedures, a continuous‐flow implementation requires a thorough consideration of the solid catalyst design. In a previous study, irregular zeolite pellets were applied in a miniaturized continuous‐flow reactor for the Diels–Alder reaction in the construction of norbornene scaffolds. After having faced the challenges of continuous operation, the aim of this study is to exploit catalyst structuring. To this end, microspheres with high uniformity and various sphere diameters were synthesized according to the vibrational droplet coagulation method. The influence of the use of these novel zeolite shapes in a mesoscale continuous‐flow Diels–Alder process of cyclopentadiene and methyl acrylate is discussed. An impressive enhancement of catalyst lifetime is demonstrated, as even after a doubled process time of 14 h, the microspheres still exceeded the conversion after 7 h when using zeolite pellets by 30 %. A dual reason is found for this beneficial impact of catalyst shaping. The significant improvement in catalyst longevity can be attributed to the interplay of the chemical composition and the porosity structure of the microspheres.

Elements of the Manufacture and Properties of Technical Catalysts

“…The reason is that transforming powders into formed bodies is a process that depends on the physicochemical properties of the powder to be shaped and on the desired characteristics of the catalyst to be produced. For example, Y zeolite can be mixed with bentonite to prepare microspheres that are used in the Diels−Alder reaction, 32 or in the form of extrudates that are used in the hydroconversion of n-octane. 33 1.2.…”

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

“…Alternative methods of catalysis have also been developed over the past few decades which offer feasible transposition to flow. Zeolite [ 432 – 433 ], heteropoly acids (HPA) [ 434 ] and other Lewis acid catalysis [ 435 ] have been exploited under flow conditions.…”

Flow Chemistry for Cycloaddition Reactions

“…[167] Another heterogeneous approach used commercially available zeolites, reaching a high conversion (� 95 %) and endoselectivity (89 : 11) for the reaction of cyclopentadiene and methyl acrylate with a throughput of 0. heterogenous batch protocol), and the robustness of the catalyst was proved during a 7 h experiment. [168]…”