The production of metal-organic frameworks by microfluidic synthesis

Metal-Organic Frameworks (MOFs), particularly Zirconium based UiO type MOFs, have been developed for a wide variety of applications in the past, such as gas storage and supporting catalysts. However, they are limited by traditionally being synthesised in long batch reactions, leading to high energy cost and potential batch to batch variations. Microfluidic synthesis can address these issues, as continuous flow reactors with increased mass/heat transfer, leading to reduced synthesis times and greater reaction control. Microfluidic synthesis has been used in this thesis to synthesise, modify, and investigate MOFs/UiO-67 in varying ways, presented in a papers format.

The first paper was published in MethodsX and describes the microfluidic synthesis of UiO-67 using a coiled flow inverter reactor. The second paper, published in the Journal of Porous Materials, describes how the crystal phase of UiO-67 can be controlled using water in the microfluidic reactor, resulting in a new product, HCP/FCC-UiO-67-Benzoic acid, being formed for the first time. The third paper, which has been submitted to the Journal of Porous Materials, describes the attempted microfluidic synthesis of Pd(0)-UiO-67-BPYDC and the several insights made on the complications present within this attempted synthesis. The final paper, which was published in the Journal of Chemical Information and Modelling, describes the formation of a machine learning model to predict the gravimetric uptake of several gasses (CO2, CH4 and H2) in MOF materials at varying pressures and temperatures. This model was fitted using experimental literature uptake data and descriptors that could be acquired without pre done modelling, to form an accurate, flexible and easy to use model for a new researcher.

This project was a success, with novel research into MOF materials through a lens of microfluidics being produced and resulting in several publications. Specific results and conclusions have been formed in each publication alongside more overarching deductions on the effects of microfluidic synthesis on MOF materials. The insights formed within this thesis may be used in future research into MOF materials and the use of microfluidics for their synthesis.