  Research towards the production of renewable chemicals for fuel and energy
industries has found lignin valorization as key. With a high carbon content and
aromaticity, a fine-tuning of the depolymerization process is required to
convert lignin into valuable chemicals. In context, model compounds have been
used to understand the electrocatalyzed depolymerization for mimicking the
typical linkages of lignin. In this investigation, 2-phenoxyacetophenone, a
model compound for lignin \b{eta}-O-4 linkage, was electro-catalytically
hydrogenated (ECH) in distinct three-electrode setups: an open and a membrane
cell. A deep eutectic solvent based on ethylene-glycol and choline chloride was
used to pursue sustainable routes to dissolve lignin. Copper was used as
electrocatalyst due to the economic feasibility and low activity towards
hydrogen evolution reaction (HER), a side reaction of ECH. By varying the cell
type, we demonstrate a simple ECH route for the generation of different
monomers and oligomers from lignin. Gas chromatography of the products revealed
a higher content of carbonyl groups in those using the membrane cell, whereas
the open cell produced mostly hydroxyl-end chemicals. Aiming at high
value-added products, our results disclose the cell type influence on
electrochemical reductive depolymerization of lignin. This approach encompasses
cheap transition metal electrodes and sustainable solvents.
