Unveiling the Structure-Performance Relationship of Co–N/C Catalysts Derived from ZnCo-ZIF: The Critical Role of Pyrolysis Temperature in HMF Oxidation

The rational design of non-noble metal catalysts relies on a deep understanding of the structure-performance relationship. Herein, we investigate the influence of pyrolysis temperature (800–1100 °C) on Co–N/C catalysts derived from ZnCo-ZIF for the aerobic oxidation of 5‑hydroxymethylfurfural (HMF) to 2,5‑furandicarboxylic acid (FDCA). A volcano‑shaped dependence of FDCA yield on pyrolysis temperature is observed, with the catalyst pyrolyzed at 1000 °C (Co–N/C-1000) delivering complete HMF conversion and 98.0% FDCA yield within 4 h under optimized conditions (110 °C, 2 MPa O 2 ). Multi-technique characterization reveals a temperature-driven evolution of Co species: from atomically dispersed Co–N x sites at 800–900 °C, to a bimodal configuration comprising abundant Co–N x together with a small amount of metallic Co 0 nanoparticles at 1000 °C, and finally to large Co aggregates at 1100 °C. The optimal catalytic performance at 1000 °C is thus attributed to this unique coexistence. Kinetic analysis confirms the consecutive pathway HMF → HMFCA → FFCA → FDCA with FFCA→FDCA as the rate‑determining step. Notably, the optimal catalyst maintains 96.8% FDCA yield under industrially relevant 5 wt% HMF concentration. This work provides insights into the structure-performance relationship of Co–N/C catalysts and a rational strategy for designing efficient non-noble metal catalysts for biomass conversion. Graphical