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.