Anisotropic nanomaterials: A new type of electrocatalyst
CIC nanoGUNE Seminars
- Speaker
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Dr. Mariana Chirea, Universidade de Vigo, Vigo, Spain
- When
-
2014/10/02
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
- iCal
**Host** : Alexander Bittner
Dendrite, star-shaped, flower-like and other anisotropic morphologies of Pt,
Au or Pd nanostructures are interesting in terms of potential catalytic
applications because they contain surfaces with high-index crystal facets,
which allow a relative abundance of active corner and edge sites.(1-3) Such
branched morphologies typically possess a high surface area, which in general
helps to increase the catalytic activity of nanoscale structures. Pt dendrites
of various porosities and Pt-Au heterostructures were used as catalysts for
ethanol oxidation reaction. Sensing, selectivity, cycleability and great
tolerance toward poisoning were demonstrated by cyclic voltammetry
measurements. Electron tomography revealed different crystalline orientations
of nanocrystallites in the nanodendrites as well as twin defects in spherical
Au particles epitaxially grown on the dendrites. The high surface area of the
dendrites (up to 22 m2 g-1) was confirmed by BET measurements, while X-ray
diffraction confirmed the abundance of high-index facets in the face-centred-
cubic crystal structure of Pt. The catalytic response of the nanostructures
reveals great potential for direct ethanol fuel cells (DEFCs) applications.
References:
(1) S. Mourdikoudis et al. Nanoscale, 2013. 5, 4776-4784
(2) S. Barbosa et al. Langmuir, 2010, 26 (18), 14943-14950
(3) S. Guo et al. ACS Nano 2010, 4 (1), 547-555