Optimized oxygen reduction activity by tuning shell component in Pd@Pt-based core-shell electrocatalysts

Combining the interests of core-shell and alloy structures, herein we report the versatile co-reduction synthesis of Pd@Pt-based core-shell nanoparticles. The current strategy can effectively tune the component of shell, from isolated Pt to binary PtNi alloy, then ternary PtNi-M (M = Fe or Cu) alloy. Further, significant improvement of oxygen reduction reaction (ORR) activity is optimized by the change in shell component. Compared to Pd@Pt/C, Pd@PtNi/C catalyst presents the ORR-helpful mass activity of 1.29 A mg(Pt)(-1). By incorporating a third metal (M) into shell layer, the optimized mass activity of Pd@PtNiFe/C and Pd@PtNiCu/C catalysts is 1.1 times and 1.4 times higher than that of Pd@PtNi/C, respectively. Meanwhile, the lower activity decays of 11.0% for Pd@PtNiFe/C and 10.6% for Pd@PtNiCu/C are obtained compared with that of Pd@PtNi/C (12.4%) after 5,000 cycles, respectively. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, Pd@Pt-based core-shell nanoparticles were successfully synthesized using a versatile co-reduction method, with the ability to effectively tune the shell component and improve the oxygen reduction reaction (ORR) activity. By incorporating a third metal into the shell layer, the activity of the catalysts was significantly enhanced, showing lower activity decay after cycling compared to the catalyst without the third metal.