Electrochemical biomass upgrading: degradation of glucose to lactic acid on a copper() electrode

• Published in: RSC advances Vol. 11; no. 5; pp. 3128 - 31218
• Main Authors: Ostervold, Lars, Perez Bakovic, Sergio I, Hestekin, Jamie, Greenlee, Lauren F
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 22.09.2021; The Royal Society of Chemistry
• Subjects: Acids; Alkalinity; Biomass; Chemistry; Conversion; Copper; Copper converters; Degradation; Electrodes; Glucose; Lactic acid; Nonrenewable resources; Oxidation; Room temperature; Selectivity; Upgrading
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra06737k

Biomass upgrading - the conversion of biomass waste into value-added products - provides a possible solution to reduce global dependency on nonrenewable resources. This study investigates the possibility of green biomass upgrading for lactic acid production by electrochemically-driven degradation of glucose. Herein we report an electrooxidized copper( ii ) electrode which exhibits a turnover frequency of 5.04 s −1 for glucose conversion. Chronoamperometry experiments under varied potentials, alkalinity, and electrode preparation achieved a maximum lactic acid yield of 23.3 ± 1.2% and selectivity of 31.1 ± 1.9% (1.46 V vs. RHE, 1.0 M NaOH) for a room temperature and open-to-atmosphere reaction. Comparison between reaction conditions revealed lactic acid yield depends on alkalinity and applied potential, while pre-oxidation of the copper had a negligible effect on yield. Post-reaction cyclic voltammetry studies indicated no loss in reactivity for copper( ii ) electrodes after a 30 hour reaction. Finally, a mechanism dependent on solvated Cu 2+ species is proposed as evidenced by similar product distributions in electrocatalytic and thermocatalytic systems. Biomass upgrading - the conversion of biomass waste into value-added products - provides a possible solution to reduce global dependency on nonrenewable resources.