Nickel–cobalt oxides decorated Chitosan electrocatalyst for ethylene glycol oxidation

Abstract

A composite of NiCo2O4 modified electrocatalyst is prepared to enhance the ethylene glycol electrooxidation. Chitosan matrix is used to improve the activity and adsorption ability of the surface to enhance ethylene glycol conversion. A Comparative study is investigated between pristine NiCo2O4 and Chitosan-modified spinel oxide to evaluate the synergistic effect between spinel oxide and chitosan. The composite is studied in an alkaline solution using electrochemistry techniques. The electrochemical activity towards ethylene glycol electrooxidation is studied as a function of anodic oxidation current density. Thus, the oxidation current values for NiCo2O4 and NiCo2O4@Chitosan in 1.0 M EG and 1.0 M KOH are 36 and 42 mA cm−2, respectively. The long-term stability of the electrode is measured by constant potential chronoamperometry. Kinetic parameters like diffusion coefficient, Tafel slope, surface coverage, and transfer coefficient are calculated. The density-functional theory estimates the adsorption of small molecules like ethylene glycol, urea, and carbon monoxide. The adsorption energy is studied on the top site of Ni and Co atoms of NiCo2O4. Forcite model is used to study the interaction between spinel oxide and chitosan. The energy calculation assumes that chitosan is adsorbed on the spinel oxide surface and enhances chitosan's ability for the adsorption of small molecules.