كليدواژه :
Palladium , Zinc ferrite , Oxidation of ethanol ,
چكيده فارسي :
Ethanol fuel cells have been more attractive due to their non-toxicity, lower volatility and higher energy density when compared to methanol. As well as, ethanol in comparison with methanol has lower cross-over through membranes owing to their larger molecular size. However, this fuel cell still faces difficulties such as poisoning, dissolution, agglomeration, and accumulation of the electrocatalyst. The use of a supports for noble metals catalysts created a reduction in the noble metal usage and improved electrocatalyst durability. In our previous work, spongy non-stochiometric zinc ferrite (ZnFe1.6O4) was synthesized by a solution combustion synthesis, and then Pd was loaded on it. In the present study, the electrocatalytic ability of Pd/ZnFe1.6O4 toward electrooxidation of ethanol was investigated using cyclic voltammetry and chronoamperometric techniques and compared with support-less Pd electrocatalyst. The results showed the Pd/ZnFe1.6O4 electrocatalyst was more successful in ethanol oxidation when compared to the support-less Pd electrocatalyst. This improvement in the oxidation process can be attributed by the selection of a suitable support for Pd. On the one hand, the spongy structure of ZnFe1.6O4 created more active sites on the modified catalyst. On the other hand, the presence of Fe as transition metal, improve the resistance of the Pd/ZnFe1.6O4 modified electrocatalyst by formation a cycle between the low and high chemical valences of Fe, and production of the oxygen network.
