NiCo2O4‐rGO/Pt as a robust nanocatalyst for sorbitol electrooxidation

A ternary nanocatalyst consisting of nickel cobalt oxide (NiCo2O4), reduced graphene oxide (rGO), and platinum (Pt) was introduced as a promising catalyst for application in the sorbitol oxidation reaction (SOR) process for use in fuel cells. Other catalysts such as NiCo2O4, NiCo2O4-rGO, and NiCo2O4/Pt were prepared for comparison. The structure and morphology of the synthesized nanocatalysts were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The efficiency of the as-synthesized materials was assessed by electrochemical tests of cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA). The comparison of the SOR process for the synthesized nanocatalysts showed that NiCo2O4-rGO/Pt has the highest current density (57.2 mA cm2, 45.04 mA/mg) at a scan rate of 10 mV/s and the lowest peak potential (0.64 V) as well as the highest cyclic stability than other materials. The superior electrocatalytic performance is attributed to the synergistic effect of the components. Moreover, the charge transfer resistance of SOR for NiCo2O4-rGO/Pt catalyst is 702 Ω, lower than that for NiCo2O4/Pt (930 Ω). Thus, NiCo2O4-rGO/Pt constitutes an efficient and promising nanocatalyst for SOR.