Defect engineering coupled with N/O Co-doping in lignin-derived carbon for enhanced ORR in anion exchange membrane fuel cells

Defect engineering coupled with heteroatom-induced electronic modulation is crucial for developing highly active metal-free carbon electrocatalysts for anion exchange membrane fuel cells (AEMFCs). However, precisely identifying active configurations in dual-heteroatom-doped carbon and controlling the ORR pathway remains challenging. Herein, we present a lignin-based supermolecule-regulated pyrolysis strategy for synthesizing N, O co-doped porous carbon (LNOC) with a large surface area of 549.7 m 2  g −1 and a hierarchical porous structure. The optimized LNOC-900 catalyst demonstrates excellent ORR activity, featuring a half-wave potential (E 1/2 ) of 0.86 V vs. RHE and a high kinetic current density (j k ) of 83.29 mA cm −2 at 0.85 V, surpassing the benchmark commercial Pt/C electrocatalyst. When employed as the cathode in AEMFCs, LNOC-900 achieves a maximum peak power density (1.05 W cm −2 ) and current density (3.30 A cm −2 ) at 0.8 V. Density functional theory (DFT) reveals that N/O co-doping and defect engineering synergistically optimize ORR intermediate adsorption, with pyridinic-N embedded in a defective sp 2 carbon matrix, facilitating O–O bond cleavage via charge density modulation at defect sites. This work presents a sustainable, low-cost path to next-generation energy storage and conversion devices.