Electrocatalytic Oxidation of Methanol on Gold Electrode Modified by Gold-Platinum Nanoparticles Dispersed Into Ag/Halloysite Nanocomposite Film

Fuel cells which are the energy converting devices with a high efficiency have been attracting more attention in recent years due to high-energy demands, fossil fuel depletions and environmental pollution throughout the world [۱]. Platinum has been used as the most popular catalyst in fuel cells for many years. However, pure Pt is much cost and it can be poisoned by CO intermediates which are produced during methanol electrooxidation [۲]. In order to improve the activity of methanol electrooxidation, a common strategy is alloying Pt with other metals, such as PtIr, PtSn and PtRu [۳,۴].In the present work, halloysite/AgNPs/ Pt –Au nanocomposite was used as an effective and novel catalyst for electrooxidation of methanol. At first, a certain amounts of halloysite and AgNPs suspensions were dropped onto the surface of the gold electrode. Then, the surface of the electrode was coated with platinum and gold (Pt –Au) nanoparticles through cyclic voltammetry technique. The surface of the modified electrode was then characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. In addition, the effects of various parameters such as methanol concentration, amount of the Ag nanoparticles and number of scan cycles of the Pt –Au nanoparticles electrodeposition on the electrooxidation of methanol were investigated and they were optimized. The electrooxidation of methanol on the surface of the modified electrode was studied using cyclic voltammetry and chronoamperometry. The obtained results show that proposed catalyst has a high electrocatalytic activity towards the methanol electrooxidation reaction as compared to Pt catalyst.