Functionalization effect of carbon support on efficiency and durability of Pt electrocatalyst toward methanol oxidation

Effective and durable catalysts toward methanol electrooxidation have the serious importance to the commercialization of direct methanol fuel cells. The current catalysts for methanol electrooxidation suffer from fast efficiency decay, inappropriately. Hence, we investigated the addition effect of un-modified and modified carbon active (C and Cm) on the performance of Pt electrocatalyst toward methanol oxidation. In order to modify carbon active as a cheap and abundant support, a vigorous oxidation process was applied. C and Cm supported Pt dispersed into the appropriate amount of chitosan polymer were prepared and their catalytic ability toward methanol oxidation was studied by electrochemical techniques such as cyclic voltammetry, chronoamperometry and linear polarization. The electrochemical active surface area, dispersion and the durability of Pt particles on modified electrodes were compared with each other. For comparison of the effect of the C and Cm addition on the electrochemical behaviour, platinum loading (= 0.51 mg/cm2) was similar on all modified electrodes. We optimized the methanol oxidation on the mentioned electrodes under the following conditions: methanol concentration, sweep rate, temperature, potential window and the concentration of H2SO4 aqueous solution as electrolyte. The incorporation of carbon structures is reliable to decrease resistant and to improve current density. The presence of functional groups on carbon structure played a determinative role in encouraging the dispersion of Pt ion before subsequent reduction.

Keywords:

carbon active , methanol oxidation , durability , fuel Cell , electrocatalyst