A Metal-Free Carbonaceous Material for Highly Efficient and Robust Electrochemical Biomass Valorization

2,5-Furandicarboxylic acid (FDCA) synthesis holds significant importance for both bio-polymer production and emerging sustainable bio-based alternatives for environmental and energy applications. Here, a metal-free carbonaceous material—that is, biomass substrate 5-hydroxymethylfurfural-derived graphene-like nitrogen doped porous carbon sheet (GNPCH)—and its application as a new catalyst for electrochemical FDCA synthesis is presented. The study scrutinized the catalytic principles, demonstrated the surprising robustness, and explored the origin of the high efficiency of GNPCH catalyzed electro-synthesis of FDCA. Initially, facial pyrolysis of 5-hydroxymethylfurfural and urea forms ultrathin GNPCH with rich micropores and defects. By employing GNPCH-900 catalyst, stable, continuous operation of >400 h with both FDCA yields and Faraday efficiencies >90% is achieved; those values not only represent the best metal-free catalyst and that are comparable to those of the state-of-the-art metal-based counterparts, but also showcase one of the longest-running electrochemical FDCA synthesis reactions. A series of electrochemical measurements, in situ characterization, and density functional theory calculations indicate that the origin of the high efficiency is mainly from the pyridinic-N-related active sites and clarify the reaction pathway. These findings suggest that the GNPCH catalyst will be a potential alternative to the metal-based catalysts in electrochemical biomass valorization.