Tunable Hollow Pt@Ru Dodecahedra via Galvanic Replacement for Efficient Methanol Oxidation

Pt–Ru nanocrystals are promising electrocatalysts for methanol oxidation in fuel cells. However, owing to the lattice mismatch and high reduction potential of Ru, the shape-controlled synthesis of Pt–Ru nanocrystals faces great challenges. Herein, we employ a galvanic replacement method to synthesize tunable hollow Pt@Ru dodecahedra via controlling the precursor concentration. Two typical structures, hollow Pt@Ru dodecahedra (h-Pt@Ru) and deformed hollow Pt@Ru dodecahedra (d-Pt@Ru), are obtained to exhibit superior electrocatalytic activities for methanol oxidation. The optimal d-Pt@Ru dodecahedra present a mass activity of 0.80 A mgPt–1 and a specific activity of 1.61 mA cmPt–2, which are 5.25 and 7.78 times higher than those of the commercial Pt/C, respectively. Remarkably, both h-Pt@Ru and d-Pt@Ru show lower oxidation potentials and higher CO-poisoning resistance for methanol oxidation than PtRu nanoparticles (NPs) and commercial Pt/C. This is attributed to the hollow dodecahedron structures with optimal spatial elemental distributions, leading to high utilization of Pt at edges and corners and the exposure of abundant Pt–Ru interfaces. Our strategy offers a facile method to engineer bimetallic metal catalysts regardless of lattice mismatch.