Titanium and platinum modified titanium electrodes as catalysts for methanol electro-oxidation

Electro-oxidation of methanol was studied on titanium and platinum modified titanium electrodes (Pt/Ti). Platinum was electro-deposited on Ti by potentiostatic and galvanostatic techniques. Electrodes prepared by the galvanostatic technique showed enhanced catalytic activity towards methanol oxidation in NaOH solution compared to those prepared by the potentiostatic method. Scanning electron microscopy and energy dispersive X-ray analysis were used to characterize the surface morphology and percent composition of Pt to Ti on the electrode surface. The catalytic activity of Pt/Ti electrode is much higher than that of Pt/Pt, bulk Ti and of pure Pt, in addition to minimizing the poisoning effect. In 3.0 M NaOH and in the presence of 2.0 M MeOH, the oxidation peak current density value of methanol after the 50th cycles reached 99.4% of its value at the first cycle for electrodes prepared by the galvanostatic method compared to 94.7% for electrodes prepared by the potentiostatic method. Polarizing the modified electrode at the hydrogen evolution potential region for a certain time was found to enhance the catalytic oxidation of methanol, while the presence of thick Ti-oxide as well as Ti-hydride inhibited the process.