Biomass upgrading using enzyme-photocatalyst coupled catalytic systems (EPCS) based on NADH
Date
2023-04-04
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Abstract
The development of sustainable methods to transform biomass into value-added products is crucial to realize the circular bioeconomy and mitigate the happening climate change. Photocatalysis and biocatalysis have emerged as two such methods in recent years. However, there are some significant obstacles for each one of them. Recently, inspired by the process of photosynthesis in nature, enzyme-photocatalyst-coupled systems (EPCSs) based on Nicotinamide adenine dinucleotide, reduced (NADH) has offered a new method that could potentially mitigate the drawbacks of each one of these methods and yield interesting synergy. In this study, we indicate the huge potential of zinc-blende (ZB) CdS as an outstanding catalyst for NADH regeneration in EPCSs with a rate of 13.1 mM/h, the highest reported in the literature, to the best of our knowledge. The catalyst shows decent stability for repeated cycles. In the second part, we report for the first time, the photoenzymatic reduction of levulinic acid, a major platform chemical derived from biomass. This serves as an example to expand the reaction spectrum of EPCSs based on NADH to enzymes and reactions beyond those that are frequently used. Almost 4 mM of levulinic acid could be reduced within 3 hours using the EPCS. During the course of this study, we also examined the importance of the sacrificial electron donor (SED) in the EPCSs, for the first time, and showed that our catalyst can accept various chemicals, especially glycerol, as SED. Besides, we report some unprecedented cross-inhibitory effects between SED and the enzyme which should be considered for future studies.
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Keywords
EPCS, enzyme, photocatalyst, biomass, NADH
Citation
Shirvani, H. (2023). Biomass upgrading using enzyme-photocatalyst coupled catalytic systems (EPCS) based on NADH (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.