Stabilization of the palladium electrocatalyst with alloyed gold for ethanol oxidation

摘要

Motivated by the idea that a monometal catalyst can become more stabilized with the incorporation of gold due to its unique electron-withdrawing effect to neighboring primary metal atoms, in this work we prepare Pd-Au alloy electrocatalysts for the ethanol oxidation reaction in an alkaline medium with the dimethylformamide co-reduction method under an ultrasonic process. The atomic ratio of Pd to Au is varied from 7:1 to 3:1 and 1:1 on the basis of a crystal cell of the face-centered cubic. Electrochemical characterizations indicate that in terms of the peak current density, the prepared catalyst samples are in sequence of Pd/C > Pd_3Au/C > Pd_7Au/C > PdAu/C, but the stability tests demonstrate that the catalyst samples are sequenced in PdAu/C > Pd_3Au/C > Pd_7Au/C > Pd/C. On the compromise between the activity and stability, it turns out that the Pd_3Au/C can exhibit an enhanced catalytic stability while maintain the comparable catalytic activity for the ethanol oxidation reaction as compared with the monometallic Pd/C catalyst.