Electro-Oxidation Ethanol Using Modified Carbon Paste Electrode with MWCNTs and VSB-5 Nanozeolite for Fuel Cell

In this study, nanoporous nickel phosphate molecular sieve VSB-5 was synthesized and characterized by X-ray diffraction and scanning electronic microscopy (SEM). The electrocatalytic oxidation of ethanol in alkaline medium has been studied using multi-walled carbon nanotubes (MWCNTs) and VSB-5 nanorods modified carbon paste electrode. The electrochemical characterizations were performed using cyclic voltammetry (CV) and chronoamperometry techniques. A sensitive oxidation peak was observed at 0.53 V in 0.1 M NaOH solution for electrocatalytic oxidation of ethanol with EC′ mechanism. The values of catalytic rate constant and diffusion coefficient for ethanol and redox sites were obtained to be 5.76×105 cm3 mol−1 s−1 and 1.49×10-7 cm2 s−1, respectively. Obtained results from cyclic voltammetry and chronoamperometric techniques specified that the electrode reaction is a diffusion-controlled process. The results show that this electrode is very attractive for application in direct ethanol fuel cell.