Electrochemical Performance of Porous Ni-Cu Anodes for Direct Methanol Fuel Cells

摘要

Transition metal 3D porous foams based on Ni and Cu were prepared using Hydrogen Bubble DynamicTemplate “DHBT” technique, from an acidic solution containing Ni-Cu salts as a source for Ni-Cudeposits. The morphology of the deposited films was affected by the current density and deposition time.At low current density and short deposition time (30 sec), smooth films composed of angular grains,with few randomly distributed isolated dendrites were detected. At high current density, typical ramifieddendritic morphology was developed. The Ni content of the deposited layer varied from 68.49- 87.86%. The electrocatalytic behavior of these layers was evaluated using potentiodynamic, cyclicvoltammetry and electrochemical impedance test in acidic 1 M methanol solution. Frompotentiodynamic test results, increasing the deposition current density as well as deposition time lead tomore anodic and current density, reflecting high electro catalytic behavior towards methanol oxidation.In addition, the forward peak intensity and total charge measured by cyclic voltammetry increased underthe effect of higher applied current density and longer deposition time having a positive effect on theelectrochemical activity of the Ni-Cu NPMFs deposited. According to EIS data, the charge transferresistance (Rp) decreased as the current density as well as electrodeposition time increased. The lowestpolarization resistance (51.7?) required for high electrocatalytic behavior was detected for porous NiCu layers electrodeposited at 2 Amp/cm2 and deposition time 150 sec.