文档介绍：was found that two forms of Fe, alloying and non-alloying Fe exist in the Pd-Fe/C catalyst. The non-alloying Fe could be dissolved in H2SO4 solution, while the alloying Fe could not be dissolved. Thus, the Pd-Fe/C catalyst with only the alloying Fe could be obtained with the acid treatment method. The electrocatalytic activity of the Pd-Fe/C catalysts before and after the acid treatment for the oxygen reduction is higher than that of the Pd/C catalyst, indicating that Fe coud increase the electrocatalytic performance of the Pd/C catalyst. In addition, the electrocatalytic performance of the Pd-Fe/C catalyst after the acid treatment for the oxygen reduction is higher than that of the Pd-Fe/C catalyst before the acid treatment, illustrating that only the alloying Fe could increase the electrocatalytic performance of the Pd/C catalyst. It is mainly due to that the alloying Fe could increase the electron density
of Pd and then increase the content of Pd0 in the catalyst. Therfore, the
electrocatalytic performance of the Pd/C catalyst for the oxygen reduction would be increased.
3. It has been firstly studied that the Pd-Fe/C catalyst was prepared with the thermal positon method using the pounds. It was found that the thermal positon temperature has the large effect on the electrocatalytic performance of the Pd-Fe/C catalysts for the the oxygen reduction. When the
thermal positon temperature is 300℃, the electrocatalytic performance of the
Pd-Fe/C catalysts for the the oxygen reduction is best. If the thermal positon temperature is low, pound can not pletely posed. However, with the increasing of the thermal positon temperature, the average size of the Pd-Fe particles increases gradually, and then the electrocatalytic performance of the Pd-Fe/C catalysts for the the oxygen reduction decrease.
The effect of the atomic ratio of Pd and Fe on the electrocatalytic performance of the Pd-Fe/C catalysts for the the oxygen reduction was further investigated. It was found th