From Pt-rich dendrites to Ni-rich cuboctahedrons: structural evolution and electrocatalytic property studies

Abstract

In this paper, we report the evolution of the composition and morphology of Pt_xNi_1−x (0 < x < 1) nanoalloys from Pt-rich dendrites to Ni-rich cuboctahedrons. However, the transformation processes were different under different temperatures. At 200 °C, the transformation was mainly completed through atomic addition, while there was a contribution from both atomic addition and oriented attachment at 220 °C. The electrocatalytic performance towards the methanol oxidation reaction (MOR) indicated the dendrites exhibited higher catalytic activity and better durability relative to the cuboctahedrons. For the cuboctahedrons with different compositions, the catalytic activity is mainly determined by the d-band position. This provides new insights into the controlled synthesis of Pt-based bimetallic nanoalloys and advances the understanding of their catalytic behaviour.