Highly Active and Durable Pt72Ru28 Porous Nanoalloy Assembled with Sub-4.0 nm Particles for Methanol Oxidation

The main challenges to the direct methanol fuel cells are the activity and durability of electrocatalysts. To alleviate such issues, a recently proposed strategy introduces an exotic element to form Pt-based alloy nanostructures. This study reports a green route to prepare porous flowerlike Pt72Ru28 nanoalloys assembled with sub-4.0 nm particles. The peak current density and mass activity on these as-synthesized porous flowerlike Pt72Ru28 nanoalloys can be increased to 10.98 mA cm(-2) and 1.70 A mg(-1) Pt for methanol oxidation in acidic medium. They are respectively 4.19/3.54, 4.27/5.0, and 5.74/1.73 times those on the commercial Pt black, Pt50Ru50 black, and Ru50Pt50/C. These porous flowerlike Pt72Ru28 nanoalloys have a much higher long-term durability than commercial Pt black, Pt50Ru50 black, and Ru50Pt50/C. More significantly, the porous Pt72Ru28 bimetallic nanoalloys have long-term solvent durability after immersion in water for 16 months. The peak current density and mass activity on porous Pt72Ru28 nanoalloys are still 7.76 mA cm(-2) and 1.2 A mg(-1) Pt. These experimental results show an effective approach to the development of PtRu nanoalloys as electrocatalysts with substantially enhanced activity and durability for direct methanol fuel cells.