Pt-Au/CNT@TiO2 as a High-Performance Anode Catalyst for Direct Methanol Fuel Cells
โ Scribed by Xiuyu WANG; Jingchang ZHANG; Hong ZHU
- Publisher
- Elsevier Science
- Year
- 2011
- Weight
- 533 KB
- Volume
- 32
- Category
- Article
- ISSN
- 1872-2067
No coin nor oath required. For personal study only.
โฆ Synopsis
Multi-walled carbon nanotubes (CNT) modified using TiO 2 nanoparticles (CNT@TiO 2 ) were prepared. Then, Pt-Au/CNT@TiO 2 catalysts were prepared by a deposition-UV-photoreduction method for direct methanol fuel cells. The physico-chemical properties of the catalysts were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic performance was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The Pt-Au nanoparticles were found to be uniformly deposited onto the CNT@TiO 2 support and had diameters of 2-3 nm. Compared with the Pt-Au/CNT catalyst that was made using a general chemical method, Pt-Au/CNT@TiO 2 exhibits higher CO-tolerance for the following reasons. Firstly, the strong interaction between the Pt-Au alloy and TiO 2 leads to an increase in electron density on the metallic Pt-Au, which transfers electrons to the CO * orbital of CO and weakens C-O binding while the oxidation overpotential is lowered. Secondly, the high-valence Ti ions dissociate water to form OH ad (ad: adsorbed) species, which then reacts with the strongly bound CO ad on the Pt surface to form CO 2 .
๐ SIMILAR VOLUMES