Lignin, a major biomass component, offers significant potential for producing high-value chemicals and renewable energy. This study introduces a novel cobalt-based electrocatalyst (CoSx@NF), synthesized via high-current density electrodeposition on nickel foam, featuring a nanoflower-like structure with exceptional electrochemical properties. In a direct lignin fuel cell (DLFC), CoSx@NF as the anode efficiently converted lignin to electricity, achieving a maximum power density of 196.1 mW‧cm-2. In an electrolytic cell, it served dual roles as anode and cathode, facilitating lignin oxidation to aromatic aldehydes and hydrogen evolution reaction (HER), respectively. At 1.2 V and 0.5 g‧L-1 lignin concentration, the total aromatic aldehyde yield reached 8.10%, with HER overpotentials of 23 mV (10 mA‧cm-2) and 153 mV (100 mA‧cm-2). A coupled DLFC-electrolytic system was developed, enabling co-production of aromatic aldehydes and hydrogen without external power. The system yielded 2.90% and 3.34% aromatic aldehydes at the DLFC and electrolytic cell anodes, respectively, alongside a hydrogen production rate of 12.7 mL‧cm-2 at the cathode. This innovative approach enhances lignin valorization and green hydrogen production, offering a sustainable strategy for biomass utilization and energy generation.
