Scaling-up of the electrochemical leaf system

<p>This thesis presents an exploration of the Electrochemical Leaf (e-Leaf) with a novel application-oriented direction. The e-Leaf, a recent breakthrough made in the Armstrong group in the area of bio-electrochemical catalysis, is inspired by the natural leaf: enzyme cascade is immobilised in...

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מידע ביבליוגרפי
מחבר ראשי: Cheng, B
מחברים אחרים: Armstrong, F
פורמט: Thesis
שפה:English
יצא לאור: 2022
נושאים:
תיאור
סיכום:<p>This thesis presents an exploration of the Electrochemical Leaf (e-Leaf) with a novel application-oriented direction. The e-Leaf, a recent breakthrough made in the Armstrong group in the area of bio-electrochemical catalysis, is inspired by the natural leaf: enzyme cascade is immobilised in the nanopores of the electrode, allowing multi-step biotransformations to be energised, controlled, and monitored in real time. Ferredoxin NADP+ reductase (FNR) is the key enzyme in the e-Leaf, catalysing the interconversion of NADP+/NADP(H). Other co-entrapped NADP(H)-dependent enzyme(s) catalyse reactions coupled to this regeneration, achieving a fast conversion due to the very high effective concentration of enzymes and short distances for cofactor and reactants to diffuse between the enzymes in the nanopores. The e-Leaf is a powerful tool for the investigation of biocatalytic processes and potentially for the production of valuable chemicals.</p> <p>In this work, the e-Leaf has been exploited for its versatility in application. First, the e-Leaf has been scaled up from a 4 mL lab-scale cell to a 500 mL pilot level reactor with new reactor designs, optimisations of the electrode construction and optimisation of reaction conditions. The productivity scales up linearly with the size of the reactor, showing the feasibility and potential of scaling up an electrochemical system.</p> <p>The e-Leaf has also been explored to function as a biphasic reactor. The introduction of an organic layer containing substrate and(or) solvent has provided the electrochemical system with a sustainable substrate supply with simultaneous relief of product-inhibition. The final step in engineering the e-Leaf has been its transformation from an original batch design into a flow reactor in which the electrochemical reactions have been performed under flow as a proof of concept. The e-Leaf therefore has the potential to work in series continuously with high space-time-yield to accommodate complex requirements for industry-level syntheses.</p> <p>In a separate branch of work, the e-Leaf has been exploited to achieve the deracemisation and stereoinversion of a secondary alcohol in a dually-controlled method, with the ability to switch the direction of the redox reaction and to change the enantioselectivity of the electrode. The reaction process is monitored in real-time to complete a one-pot, one-step deracemisation (or stereoinversion).</p>