Shape-Control of Pt-Ru Nanocrystals: Tuning Surface Structure for Enhanced Electrocatalytic Methanol Oxidation

Despite the fact that both electrochemical experiments and density functional theory calculations have testified to the superior electrocatalytic activity and CO-poisoning tolerance of platinuim ruthenium (PtRu) alloy nanoparticleS toward the methanol oxidation reaction (MOR), the facet-dependent electrocatalytic properties of PtRu nanopartides are scarcely- revealed because it is extremely difficult to synthesize well-defined facets enclosed PtRu nanocrystals. Herein, we for the first time report a general synthesis of ultrathin PtRu nanocrystals with tunable morphologies (nanowires,, nanorods, and nanocubes) through one-step solvothermal approach and a systematic investigation of the structure-directing effects of:different surfactants, and the formation mechanism by control experiments and title-dependent studies. In addition, we utilize these {100} and {111} facets enclosed PtRu,nanocrystals as model catalysts to evaluate the electrocatalytic characteristics of the MOR on different Remarkably, {111}-terminated-PtRu nanowires exhibit much higher stability and electrocatalytic mass activity toward MOR, which are 2.28 and 4.32 times higher than those of {100}-terminated PtRu nanocubes and commercial Pt/C, respectively, indicating that PtRu {111} facets possess superior methanol oxidation activity and CO-poisoning resistance relative to {100} facets. Our present work provides a series of well-defined PtRu nanocrystals with tunable facets which would be ideal model electrocatalysts for fundamental research in fuel cell electrocatalysis.