Near-monolayer platinum shell on core-shell nanocatalysts for high-performance direct methanol fuel cell

We investigate the Ru_core-Pt_shell nanoparticles (NPs) with near-monolayer thick shell atoms as the electrocatalysts at anode in the direct methanol fuel cell (DMFC). The results of X-ray diffraction indicate that its crystal structure experienced a compressive strain in Pt shell region. The shell thickness of Ru_core-Pt_shell NPs was determined to be 1.5 atomic layers by small-angle X-ray scattering by using a core-shell scattering model, and the surface atomic morphology was illustrated via high-resolution transmission electron microscopy (HRTEM). Compared with the Pt NPs, the power density of DMFC with Ru_core-Pt_shell NPs was improved by ∼450% (from 17.1 to 92.8 mW cm^-2 mg^-1), and the open-circuit voltage was improved by 0.18 V (from 0.49 to 0.67 V). Our results fulfill the development of cost-effective DMFC with outstanding performance.