Scalable Continuous Flow Metal–Organic Framework (MOF) Synthesis Using Supercritical CO₂

Abstract

The high surface areas and tunable porous structures of Metal−Organic Framework (MOF) materials offer desirable capabilities in a wide range of applications. One challenge to the widespread use of MOFs is a lack of large-scale manufacturing synthesis processes. This paper presents a novel method of continuous synthesis of MOF using supercritical carbon dioxide (scCO 2 ), introduced through a custom counter-current mixer, to provide enhanced heat and mass transfer to MOF precursor materials. The method was used to synthesize the zirconium-based MOF UiO-66 at a production rate of 104 g/h. Synthesis of UiO-66 was confirmed via SEM images, powder X-ray diffraction (PXRD) spectra, and physisorption analysis. Additionally, testing showed that this method could be used to activate as well as continuously synthesize MOF materials. Our method results in rapid reaction time (<3s), can be easily scaled, and it allows for recovery of effluent and unreacted material, which is challenging in hydrothermal and supercritical water-based systems.

Accelerated Synthesis of a Ni2Cl2(BTDD) Metal–Organic Framework in a Continuous Flow Reactor for Atmospheric Water Capture

“…The use of flow chemistry to achieve product intensification by improving heat and mass transfer, decreasing the use of solvents, and improving scalability through parallelization has transformed many disciplines, including polymer chemistry, organic synthesis, − and photochemistry . Numerous studies over the past decade have demonstrated the feasibility of synthesizing MOFs in flow; − however, the influence of synthetic parameters on product crystallinity and scale-up strategies for high-throughput manufacturing by considering transport processes have not been explored thoroughly. Here, we investigate the use of flow reactors for the accelerated synthesis of Ni 2 Cl 2 (BTDD) under mild solvothermal conditions.…”

A continuous flow chemistry approach for the ultrafast and low-cost synthesis of MOF-808

“…33 To this end, we surmised that switching the synthesis of MOF-808 from batch to flow would improve our understanding of early stage crystallization processes as well as provide an alternative low-cost and high-throughput route to match industrial-scale production at competitive market prices. 34,35 Numerous studies over the past few years have demonstrated the benefits of synthesizing MOFs in flow, [36][37][38][39][40][41][42][43][44] however, the influence of synthetic parameters on product crystallinity and scale-up strategies for high-throughput manufacturing have not been explored thoroughly. Only a handful of studies 37,45 have established the feasibility of synthesizing MOF-808 in flow, but a comprehensive understanding on the influence of synthetic parameters on product crystallinity, pathways to achieve high process yields, and solvent use optimization have not been explored in detail.…”

High-throughput Screening of Vanadium (IV) Oxide via Continuous Hydrothermal Flow Synthesis Reactor

“…Here, the mixing section length is defined as the distance from the end of the inner inlet pipe to the reactor section pipe's centerline as commonly done in counter current mixing sections. 29 The volume for the flow in the reactor section was defined by the inner diameter of the reactor section pipe and the length of the reactor section. The density of the fluid in the mixing and reactor sections was defined from NIST RefProp at the isobaric pressure of 23.5 MPa and using the thermocouple data, T5, for the temperature of the colloidal solution exiting the mixing section.…”