Highly branched Pt–Ni nanocrystals enclosed by stepped surface for methanol oxidation

Integrated design of nanocatalysts with a preferential surface atomic arrangement, composition, and overall morphology will provide great opportunities to enhance their catalytic activity and durability. In this work, Pt–Ni bimetallic nanobundles (NBs) with branched morphology and stepped surfaces have been prepared by a seed-based diffusion method. For methanol oxidation, the Pt–Ni NBs possess 3.6-fold the activity of conventional Pt nanoparticles (NPs), likely due to the high-density surface atomic steps and the presence of surface Ni species. With the aggregation resistant starlike morphology, the Pt–Ni NBs pertain 55% of initial peak current density after 4000 cycles, while conventional Pt NPs maintain only 10% of that.