Fe-N-C matrix integrated with Selenium-modified-MXene to enhance oxygen reduction reaction

Iron-nitrogen-carbon (Fe-N-C) materials have attracted considerable attention as promising noble-metal-free catalysts for the oxygen reduction reaction (ORR), yet their activity and durability remain limited. In this work, an integrated composite structure was rationally designed and constructed by Fe-N-C matrix integrated with Selenium-modified-MXene. This integrated architecture may facilitate electron transport, reactant accessibility, and intermediate conversion during ORR. X-ray photoelectron spectroscopy (XPS) analyses indicate possible electronic interactions among Se species, Fe-N x coordination structures, and the MXene framework within the multiphase catalyst, which contribute to enhanced ORR kinetics. Meanwhile, the highly conductive MXene-derived component facilitate electron transport and interfacial charge transfer, improving the electrochemical reaction environment and interfacial stability. Benefiting from the synergistic interactions among Fe-N x coordination structures, Se-related species, and MXene interfaces, the resulting Se-MX@Fe-N-C catalyst exhibits good ORR activity, delivering a half-wave potential ( E 1/2 ) of 0.901 V, which is superior to commercial Pt/C (0.865 V), along with high power density (131.9 mW cm –2 ), large current density (257.3 mA cm –2 ), good Zn utilization capacity (761.8 mAh g Zn –1 ), and good cycling stability of up to 167 h when applied as the air cathode in Zinc-air batteries. This work offers insights into the rational design of multiphase Fe-N-C-based systems for efficient and durable energy conversion.