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Preparation of a platinum electrocatalyst by coaxial pulse arc plasma deposition

View Article: PubMed Central - PubMed

ABSTRACT

We have developed a new method of preparing Pt electrocatalysts through a dry process. By coaxial pulse arc plasma deposition (CAPD), highly ionized metal plasma can be generated from a target rod without any discharged gases, and Pt nanoparticles can be deposited on a carbon support. The small-sized Pt nanoparticles are distributed over the entire carbon surface. From transmission electron microscopy (TEM), the average size of the deposited Pt nanoparticles is estimated to be 2.5 nm, and their size distribution is narrow. Our electrocatalyst shows considerably improved catalytic activity and stability toward methanol oxidation reaction (MOR) compared with commercially available Pt catalysts such as Pt black and Pt/carbon (PtC). Inspired by its very high efficiency toward MOR, we also measured the catalytic performance for oxygen reduction reaction (ORR). Our PtC catalyst shows a better performance with half-wave potential of 0.87 V, which is higher than those of commercially available Pt catalysts. The higher performance is also supported by a right-shifted onset potential. Our preparation is simple and could be applied to other metallic nanocrystals as a novel platform in catalysis, fuel cells and biosensors.

No MeSH data available.


(a) SEM image, (b) HAADF-STEM image and (c) and (d) bright-field TEM images of Pt nanoparticles (5 wt%) deposited on carbon support. The corresponding histogram of the particle size distribution is also shown as the inset in panel (c).
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Figure 2: (a) SEM image, (b) HAADF-STEM image and (c) and (d) bright-field TEM images of Pt nanoparticles (5 wt%) deposited on carbon support. The corresponding histogram of the particle size distribution is also shown as the inset in panel (c).

Mentions: A scanning electron microscope (SEM) image of the PtC catalyst prepared by CAPD is shown in figure 2(a). The surface topography indicates that small-sized Pt nanoparticles are distributed over the entire carbon surface. In figure 2(b), the high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image shows the location of the Pt nanoparticles, which are mostly deposited on the carbon surface. To further characterize the deposit, the samples were observed by high-resolution transmission electron microscopy (HRTEM). As seen from the bright-field TEM image (figure 2(c)), the average size of the deposited Pt nanoparticles is estimated to be 2.5 nm, and their particle size distribution is narrow. Each deposited particle is well crystalized. The observed d spacing of 0.23 nm between two adjacent fringes can be assigned to the (111) diffraction planes of the face-centered cubic fcc Pt crystal structure (figure 2(d)) [29, 30]. The electronic state of Pt was characterized by x-ray photoelectron spectroscopy (XPS). The position of the doublet peaks at binding energies of 74.4 eV and 71.0 eV can be assigned to the Pt0 4f5/2 and Pt0 4f7/2 components, respectively, which indicates the formation of metallic Pt.


Preparation of a platinum electrocatalyst by coaxial pulse arc plasma deposition
(a) SEM image, (b) HAADF-STEM image and (c) and (d) bright-field TEM images of Pt nanoparticles (5 wt%) deposited on carbon support. The corresponding histogram of the particle size distribution is also shown as the inset in panel (c).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036468&req=5

Figure 2: (a) SEM image, (b) HAADF-STEM image and (c) and (d) bright-field TEM images of Pt nanoparticles (5 wt%) deposited on carbon support. The corresponding histogram of the particle size distribution is also shown as the inset in panel (c).
Mentions: A scanning electron microscope (SEM) image of the PtC catalyst prepared by CAPD is shown in figure 2(a). The surface topography indicates that small-sized Pt nanoparticles are distributed over the entire carbon surface. In figure 2(b), the high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) image shows the location of the Pt nanoparticles, which are mostly deposited on the carbon surface. To further characterize the deposit, the samples were observed by high-resolution transmission electron microscopy (HRTEM). As seen from the bright-field TEM image (figure 2(c)), the average size of the deposited Pt nanoparticles is estimated to be 2.5 nm, and their particle size distribution is narrow. Each deposited particle is well crystalized. The observed d spacing of 0.23 nm between two adjacent fringes can be assigned to the (111) diffraction planes of the face-centered cubic fcc Pt crystal structure (figure 2(d)) [29, 30]. The electronic state of Pt was characterized by x-ray photoelectron spectroscopy (XPS). The position of the doublet peaks at binding energies of 74.4 eV and 71.0 eV can be assigned to the Pt0 4f5/2 and Pt0 4f7/2 components, respectively, which indicates the formation of metallic Pt.

View Article: PubMed Central - PubMed

ABSTRACT

We have developed a new method of preparing Pt electrocatalysts through a dry process. By coaxial pulse arc plasma deposition (CAPD), highly ionized metal plasma can be generated from a target rod without any discharged gases, and Pt nanoparticles can be deposited on a carbon support. The small-sized Pt nanoparticles are distributed over the entire carbon surface. From transmission electron microscopy (TEM), the average size of the deposited Pt nanoparticles is estimated to be 2.5 nm, and their size distribution is narrow. Our electrocatalyst shows considerably improved catalytic activity and stability toward methanol oxidation reaction (MOR) compared with commercially available Pt catalysts such as Pt black and Pt/carbon (PtC). Inspired by its very high efficiency toward MOR, we also measured the catalytic performance for oxygen reduction reaction (ORR). Our PtC catalyst shows a better performance with half-wave potential of 0.87 V, which is higher than those of commercially available Pt catalysts. The higher performance is also supported by a right-shifted onset potential. Our preparation is simple and could be applied to other metallic nanocrystals as a novel platform in catalysis, fuel cells and biosensors.

No MeSH data available.