Fei Gao

Ethylene Glycol Electrooxidation Based on Pentangle-Like PtCu Nanocatalysts

The research of active and stable electrocatalysts toward liquid-fuel oxidation reaction is of great significance for the large-scale commercialization of fuel cells. Although extensive efforts have been devoted to pursuing high-performance nanocatalysts for fuel cells, both the high cost and sluggish reaction kinetics have been two major drawbacks that limited its commercial development. In this regard, we demonstrated a facile solvothermal method for the syntheses of an advanced class of PtCu nanocatalysts with a unique pentangle-like shape. By combining the merits of a highly active surface area as well as the synergistic and electronic effects, the as-prepared pentangle-like Pt3 Cu nanocatalysts showed superior electrocatalytic activity towards ethylene glycol oxidation with a mass and specific activities of 5162.6u2005mAu2009mg-1 and 9.7u2005mAu2009cm-2 , approximately 5.0 and 5.1u2005times higher than the commercial Pt/C, respectively. More significantly, the Pt3 Cu pentangle also showed excellent long-term stability with less activity decay and negligible changes in structure after 500u2005cycles, indicating another class of anode catalysts for fuel cells and beyond.

Rapid synthesis of platinum-ruthenium bimetallic nanoparticles dispersed on carbon support as improved electrocatalysts for ethanol oxidation

Bimetallic nanocatalysts with small particle size benefit from markedly enhanced electrocatalytic activity and stability during small molecule oxidation. Herein, we report a facile method to synthesize binary Pt-Ru nanoparticles dispersed on a carbon support at an optimum temperature. Because of its monodispersed nanostructure, synergistic effects were observed between Pt and Ru and the PtRu/C electrocatalysts showed remarkably enhanced electrocatalytic activity towards ethanol oxidation. The peak current density of the Pt1Ru1/C electrocatalyst is 3731u202fmAu202fmg-1, which is 9.3 times higher than that of commercial Pt/C (401u202fmAu202fmg-1). Furthermore, the synthesized Pt1Ru1/C catalyst exhibited higher stability during ethanol oxidation in an alkaline medium and maintained a significantly higher current density after successive cyclic voltammograms (CVs) of 500 cycles than commercial Pt/C. Our work highlights the significance of the reaction temperature during electrocatalyst synthesis, leading to enhanced catalytic performance towards ethanol oxidation. The Pt1Ru1/C electrocatalyst has great potential for application in direct ethanol fuel cells.

Particle size effects of PtAg nanoparticles on the catalytic electrooxidation of liquid fuels

A tailored design of highly efficient Pt-based bimetallic nanocatalysts for the electrooxidation of liquid fuel offers a promising approach for the commercialization of fuel cells. Although extensive researches on seeking high-performance Pt-based nanocrystals for electrocatalytic reactions have been conducted, the particle size effects of bimetallic Pt-based nanoparticles (NPs) on the fuel cell reaction remain unclear. In this regard, we herein report a size-controlled synthesis of bimetallic Pt–Ag NPs. By varying the amount of phloroglucinol involved in the reaction, Pt–Ag NPs with variable sizes from 7.5 to 15.0 nm can be prepared. By virtue of the unique particle size effects, abundant active sites on the surface as well as the synergistic and electronic effects due to Pt and Ag, these Pt–Ag NPs with the smallest particle size exhibit the best electrocatalytic activities for ethylene glycol and glycol oxidation reactions, and the electrocatalytic activities of Pt–Ag NPs are as much as 3.1 and 3.4 times higher when compared with those of the commercial Pt/C catalysts. This research can provide significant guidelines for the size selection of bimetallic Pt-based nanocatalysts with both enhanced activity and durability for fuel cell reactions.

High-Quality Platinum-Iron Nanodendrites with a Multibranched Architecture as Efficient Electrocatalysts for the Ethanol Oxidation Reaction

Although great success has been made in the design of well‐defined nanocrystals (NCs) with various morphologies, a facile method to prepare desirable NCs with large active surface areas and unique facets remains an arduous challenge. Herein, we demonstrate a facile method for the successful synthesis of high‐quality PtFe nanodendrites with a multibranched architecture; these nanodendrites have an abundance of exposed surface active sites that are available for ethanol molecules. Detailed study of its electrocatalytic properties revealed that the resultant superbranched PtFe nanocatalysts displayed superior electrocatalytic activity towards ethanol oxidation with unprecedentedly high mass/specific activities of 3692.5u2005mAu2009mg−1 and 7.02u2005mAu2009cm−2; these values are 9.3 and 10.0‐fold higher than those of a commercial Pt/C catalyst, signifying that the these nanodendrites may serve as highly efficient catalysts for fuel cells and beyond.