Structural and Compositional Behaviors of Shaped Pt Alloy Nanoparticle Electrocatalysts

摘要

We present the design and synthesis of phase segregated Pt alloy nanoparticle electrocatalysts through a facile solvothermal route in a dimethylformamide solvent. The compositional segregation near the alloyed PtNi nanoparticle surface was achieved by controlling the reaction kinetics and site-dependent compositional segregation in the facet centers of the shaped Pt_xNi_(1-x) nanoparticles was controlled by the bulk Pt/Ni composition ratio, respectively. Based on this unique compositional segregation, we study their atomicscale evolution of surface microstructure and composition by using high-resolution scanning transmission electron microscopy with high angle annular dark field and electron energy loss spectroscopy line scans and investigate their structural and compositional behaviors under reactive environments. The surface evolution of these materials helps ones understand the reactivity and degradation of a catalyst and understand the interactions between reactants and catalysts by introducing environmental impact factors.