Electrochemical Cellobiose Valorization: Anodic Oxidation to Cellobionic Acid and Cathodic Reduction to Cellobitol

Abstract

This study elucidates key parameters allowing the electrochemical valorization of cellobiose, by creating value-added products by both, anodic oxidation, and cathodic reduction. We demonstrate the first electrochemical reduction of cellobiose to cellobitol in a divided cell using Pb as cathode, leading up to 49 % conversion, though with long reaction times (over 26 h) and low coulombic efficiency (CE) of 4 %. The successful synthesis of cellobionic acid was demonstrated by mediated oxidation in an undivided electrochemical cell, using a graphite anode and CaBr 2 as electrocatalytic mediator. Cellobiose oxidation was highly selective, allowing for up to 92 % conversion to cellobionic acid at 48 % CE when using a charge of 2 FE.

Progress in Biomass Electro‐Valorization for Paired Electrosynthesis of Valuable Chemicals and Fuels

“…Cellobiose is a disaccharide made up of two glucose molecules linked by a β‐1,4 glycosidic bond, and is the smallest monomer making up cellulose. Morejón et al [ 240 ] produced cellobionic acid from cellobiose by using a hypobromite/bromide redox couple as a mediator on graphite anodes in an undivided electrochemical cell. They achieved a 92% selectivity toward cellobionic acid and 48 % Coulombic efficiency at 0.25 A cm −2 when using a charge of 2 FE (conditions: 0.25 M cellobiose, 0.25 M CaCO 3 , 50 wt% CaBr 2 , D 2 O, 4 mL batch, 0 °C).…”