Article

Self-supported interconnected Pt nanoassemblies as highly stable electrocatalysts for low-temperature fuel cells.

School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore.
Angewandte Chemie International Edition (Impact Factor: 11.34). 06/2012; 51(29):7213-6. DOI: 10.1002/anie.201201553
Source: PubMed

ABSTRACT In it for the long haul: Clusters of Pt nanowires (3D Pt nanoassemblies, Pt NA) serve as an electrocatalyst for low-temperature fuel cells. These Pt nanoassemblies exhibit remarkably high stability following thousands of voltage cycles and good catalytic activity, when compared with a commercial Pt catalyst and 20 % wt Pt catalyst supported on carbon black (20 % Pt/CB).

0 Bookmarks
 · 
285 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Well-defined noble metal nanocrystals (NMNCs) of a unique morphology yet a uniform facet have attracted broad interests. In this regard, those with a highly branched architecture have gained particular attention. Most of the currently existing branched NMNCs, however, are enclosed by mixed facets. We now report that branched Au nanoarchitectures could be facilely fabricated by mixing an aqueous solution of KAuCl4, an aqueous dispersion of graphene oxide, and ethanol under ambient conditions. Interestingly, unilike the conventional branched NMNCs, our unique Au nanostructures are predominately enriched with a uniform facet of {111}. Compared to the spherical Au nanostructures exposed with mixed facets, our branched nanospecies of a uniform facet display superior catalytic performances both for the catalytic reduction of 4-nitrophenol and the electrocatalytic oxidation of methanol. Our investigation represents the first example that Au nanostructures simultaneously featured with a highly branched architecture and a uniform crystal facet could be formulated. Our unique Au nanostructures provide a fundamental yet new scientific forum to disclose the correlation between the surface atomic arrangement and the catalytic performances of branched NMNCs.
    Scientific reports. 01/2014; 4:5259.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nitrogen self-doped porous carbon was prepared by calcination treatment of surplus sludge, a toxic by-product from microbial wastewater treatments, and exhibited a mesoporous structure, as manifested in scanning and transmission electron microscopic measurements. Nitrogen adsorption/desorption studies showed that the porous carbon featured a BET surface area as high as 310.8 m2/g and a rather broad range of pore size from 5 to 80 nm. X-ray photoelectron spectroscopic studies confirmed the incorporation of nitrogen into the graphitic matrix forming pyridinic and pyrrolic moieties. Interestingly, the obtained porous carbon exhibited apparent electrocatalytic activity in oxygen reduction in alkaline media, with the optimal temperatures identified within the range of 600 to 800 oC, where the number of electron transfer involved in oxygen reduction was estimated to be 3.5 to 3.7 and the performance was rather comparable to leading literature results as a consequence of deliberate engineering of the graphitic matrix by nitrogen doping.
    ACS Applied Materials & Interfaces 08/2014; · 5.90 Impact Factor
  • Source

Full-text

Download
341 Downloads
Available from
May 17, 2014