Magnesium-templated Fe-N doped carbon materials from biomass waste as electrocatalysts for oxygen reduction reaction in alkaline media
Fe-N-C electrocatalysts derived from Posidonia oceanica biomass were synthesized using a dual-template approach with MgO nanoparticles and MgCl₂·6H₂O to enhance electrocatalytic activity for the oxygen reduction reaction (ORR). The electrocatalysts, designed as Fe-N-C (MgO) and Fe-N-C (MgO@MgCl2), w...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/744200 |
| Acceso en línea: | https://hdl.handle.net/10486/744200 https://dx.doi.org/10.1016/j.electacta.2025.146899 |
| Access Level: | acceso abierto |
| Palabra clave: | Electrocatalysis Fe-N-C electrocatalyst oxygen reduction reaction carbon materials waste valorisation Química |
| Sumario: | Fe-N-C electrocatalysts derived from Posidonia oceanica biomass were synthesized using a dual-template approach with MgO nanoparticles and MgCl₂·6H₂O to enhance electrocatalytic activity for the oxygen reduction reaction (ORR). The electrocatalysts, designed as Fe-N-C (MgO) and Fe-N-C (MgO@MgCl2), were characterized by N2 sorption analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDXS), X-Ray diffraction (XRD), Raman spectroscopy, X-Ray Photoelectron Spectroscopy (XPS), and inductively coupled plasma optical emission spectroscopy (ICP-OES). Fe-N-C (MgO@MgCl₂) exhibited a high specific surface area of 1075 m²/g and a micropore volume of 0.466 cm³/g, as well as a homogenous distribution of Fe species. Electrochemical analyses, including double-layer capacitance measurements, indicated that incorporating MgCl2·6H2O as a template in Fe-N-C (MgO@MgCl₂) synthesis significantly increased the electrochemically active surface area (ECSA) (177.5 cm2 vs. 127.5 cm2 for Fe-N-C (MgO)), which is essential for effective ion transport and ORR kinetics. Rotating disk electrode (RDE) tests revealed superior ORR performance of Fe-N-C (MgO@MgCl₂) in alkaline media (0.1 M KOH), with a kinetic current (ik) of -0.70 mA at 0.8 VRHE and mass activity of 13.7 A g-1, outperforming Fe-N-C (MgO) which showed values of -0.26 mA and 5.2 A g-1, respectively. Stability tests showed that Fe-N-C (MgO@MgCl₂) maintained 90.4 % of its kinetic current after 8000 cycles in RDE under O2-saturation, highlighting its robust durability. These results demonstrate that the hierarchical porous structure achieved by dual templating effectively enhances the electrocatalytic activity and stability of Fe-N-C materials for ORR, positioning biomass-derived electrocatalysts as a sustainable alternative to conventional electrocatalysts |
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