Loading...

Electrocatalytic oxidation of methanol and glucose on NiCu alloy electrode

Danaee, I ; Sharif University of Technology

113 Viewed
  1. Type of Document: Article
  2. Abstract:
  3. Nickel-copper alloy modified glassy carbon electrodes (GC/NiCu) prepared by galvanostatic deposition were examined for their redox process and electrocatalytic activities towards the oxidation of methanol and glucose in alkaline solutions. The methods of cyclic voltammetery (CV), chronoamperometry (CA) and impedance spectroscopy (EIS) were employed. The cyclic voltammogram of NiCu alloy demonstrates the formation of β/β crystallographic forms of the nickel oxyhydroxide under prolonged repetitive potential cycling in alkaline solution. In CV studies, in the presence of methanol NiCu alloy modified electrode shows a significantly higher response in oxidation reaction. The peak current of the oxidation of nickel hydroxide increase is followed by a decrease in the corresponding cathodic current in presence of methanol and glucose. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of methanol and glucose was found to be 2×10-6 and 1×10-5 cm2 s-1 in agreement with the values obtained from CV measurements. The impedance behavior show different patterns, capacitive, and inductive loops and negative resistances, at different applied anodic potential. The influence of the electrode potential on the impedance pattern is studied and a quantitative explanation for the impedance behavior of oxidation reaction is put forward by a proposed mathematical model. The conditions required for the reversing of impedance pattern are delineated with the use of the impedance model. The previously proposed electrooxidation mechanism on GC/NiCu electrode was found to reproduce the experimental impedance plots
  4. Keywords:
  6. Source: Copper Alloys: Preparation, Properties and Applications ; 2011 , Pages 1-44 ; 9781612095042 (ISBN)
  7. URL: http://www.sciencedirect.com/science/article/pii/S0360319908006125