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

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 ${CE}$ ) of 4 %. The successful synthesis of cellobionic acid was demonstrated by mediated oxidation in an undivided electrochemical cell, using a graphite anode and CaBr2 as electrocatalytic mediator. Cellobiose oxidation was highly selective, allowing for up to 92 % conversion to cellobionic acid at 48 % CE ${CE}$ when using a charge of 2 FE.