Electrocatalytic Lignin Valorization via Enhanced H₂O₂ Generation Using a MWNCT-Modified Gas Diffusion Electrode

Abstract

The electrocatalytic valorization of lignin provides a sustainable route to valuable chemicals under mild conditions, yet achieving high efficiency and selectivity remains challenging. Here, we develop gas diffusion electrodes (GDEs) modified with few-layer graphene (GR) and multi-walled carbon nanotubes (MWCNT) to enhance the oxygen reduction reaction (ORR) for efficient hydrogen peroxide (H₂O₂) generation. The MWCNT-modified GDE exhibits the highest surface area and conductivity, achieving over 80 % selectivity for H₂O₂ via the two-electron ORR pathway. Electrochemical lignin depolymerization using this optimized GDE yields 72.3 % low-molecular-weight aromatic compounds within 1 h. The MWCNT-GDE demonstrates exceptional durability, maintaining stable performance across ten consecutive cycles. This work highlights the potential of MWCNT-modified electrodes to advance scalable electrochemical lignin valorization through in-situ H₂O₂ generation.