A Novel Co ₃ Se ₄ ‐CNFs Hybrid System as a Versatile Enhancer for Pd NPs Toward Ethylene Glycol Electrooxidation

Abstract The commercialization of fuel cells requires electrocatalysts with improved electrocatalytic activity, stability, durability, and reduced cost. Pd nanoparticles supported on cobalt selenide‐carbon nanofibers (Pd/Co ₃ Se ₄ ‐CNFs) are synthesized using a modified polyol‐microwave sodium borohydride reduction method for the electrocatalytic oxidation of ethylene glycol. The electrochemical evaluation employs cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA) for stability, while electrochemical impedance spectroscopy (EIS) assesses the electrocatalyst conductivity. Pd NPs on Co ₃ Se ₄ ‐CNFs are analyzed through X‐ray photoelectron spectroscopy (XPS) and X‐ray diffraction (XRD), with morphology studied using transmission electron microscopy (TEM). The Pd/Co ₃ Se ₄ ‐CNFs exhibited excellent electrocatalytic properties in an alkaline medium due to strong metal‐support interactions (SMSI), synergy, electronic interactions, and good dispersion. The electrochemically active surface area (ECSA) of Pd/Co ₃ Se ₄ ‐CNFs is 98.1 m ² g ⁻¹ , mass activity of 2716.7 mA mg _Pd ⁻¹ , which is 14.2 times more than Pd/C _commercial electrocatalyst, which produced 191.2 mA mg _Pd ⁻¹ . Also, Pd/Co ₃ Se ₄ ‐CNFs has high stability for 2.78 h and excellent durability after 500 cycles, retaining 65.7% current density. These findings reveal the Co ₃ Se ₄ ‐CNFs hybrid as a novel support that enhances the electronic interaction with Pd nanoparticles, significantly improves catalyst durability, and imparts strong resistance to poisoning during ethylene glycol electrooxidation, offering a robust platform for advanced alcohol fuel cell catalysis.