Study of the efficiency of porous zinc ferrite non-stochiometricsupport in ethanol electrooxidation

Ethanol fuel cells have been more attractive due to their non-toxicity, lower volatility and higher energydensity when compared to methanol. As well as, ethanol in comparison with methanol has lower crossoverthrough membranes owing to their larger molecular size. However, this fuel cell still facesdifficulties such as poisoning, dissolution, agglomeration, and accumulation of the electrocatalyst. Theuse of a supports for noble metals catalysts created a reduction in the noble metal usage and improvedelectrocatalyst durability. In our previous work, spongy non-stochiometric zinc ferrite (ZnFe۱.۶O۴) wassynthesized by a solution combustion synthesis, and then Pd was loaded on it. In the present study, theelectrocatalytic ability of Pd/ZnFe۱.۶O۴ toward electrooxidation of ethanol was investigated using cyclicvoltammetry and chronoamperometric techniques and compared with support-less Pd electrocatalyst.The results showed the Pd/ZnFe۱.۶O۴ electrocatalyst was more successful in ethanol oxidation whencompared to the support-less Pd electrocatalyst. This improvement in the oxidation process can beattributed by the selection of a suitable support for Pd. On the one hand, the spongy structure ofZnFe۱.۶O۴ created more active sites on the modified catalyst. On the other hand, the presence of Fe astransition metal, improve the resistance of the Pd/ZnFe۱.۶O۴ modified electrocatalyst by formation acycle between the low and high chemical valences of Fe, and production of the oxygen network.

کلیدواژه ها:

Palladium ، Zinc ferrite ، Oxidation of ethanol ، Porous support