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Reducing the Pt-based electrocatalysts to sub-nanometer sizes is an effective way to achieve high utilization of noble metals. Herein, we report a successive route to synthesize carbon-supported bimetallic ruthenium-platinum electrocatalysts (Ru-Pt/C) with uniform dispersion and fine sizes. In this strategy, carbon-supported Ru nanoparticles (Ru/C) with a mean size of 1.4 nm are firstly prepared in a mixture of ethylene glycol and water, and the Pt precursors are then reduced in the presence of pre-formed Ru/C. The average diameter of the bimetallic Ru-Pt particles on carbon supports is 1.9 nm, which corresponds to one to two Pt layers deposited on the surface of Ru seeds. The as-prepared bimetallic Ru-Pt/C electrocatalysts are analyzed by the CO stripping voltammetry, a diagnostic electrochemical tool. Compared with the commercial PtRu/C catalyst and the control PtRu/C prepared by a conventional co-reduction method, the bimetallic Ru-Pt/C has higher electrochemical surface area (92.5 m g) and mass activity (483 A g) for methanol oxidation reaction. The strategy reported in this study is effective to produce fine bimetallic Ru-Pt particles (less than 2.0 nm) with uniform dispersion and high activity. [ABSTRACT FROM AUTHOR]

Zn-doped LiNi1/3Co1/3Mn1/3O2 composite, Li(Ni1/3Co1/3Mn1/3)1–xZnxO2 (x = 0.02; 0.05; 0.08), is synthesized by the sol-gel method. The crystal structure, morphology, and electrochemical performance are investigated via X-ray diffraction (XRD), scanning electron microscope (SEM), cyclic voltammetry (CV), and constant current charge/discharge experiment. The result reveals that Zn-doping cathode material can reach the initial charge/discharge capacity of 188.8/162.9 mAh·g−1 for Li(Ni1/3Co1/3Mn1/3)0.98Zn0.02O2 and 179.0/154.1 mAh·g−1 for Li(Ni1/3Co1/3Mn1/3)0.95Zn0.05O2 with the high voltage of 4.4 V at 0.1 C. Furthermore, the capacity retention of Li(Ni1/3Co1/3Mn1/3)0.98Zn0.02O2 is 95.1% at 0.5 C after 50 cycles at room temperature. The improved electrochemical properties of Zn-doped LiNi1/3Co1/3Mn1/3O2 are attributed to reduced electrode polarization, enhanced capacity reversibility, and excellent cyclic performance. [ABSTRACT FROM AUTHOR]