Temperature Dependence of Oxygen Reduction Activity at Carbon-Supported PtXCo (X = 1, 2, and 3) Alloy Catalysts Prepared by the Nanocapsule Method

Yano, Hiroshi; Song, Jung Min; Uchida, Hiroyuki; Watanabe, Masahiro

doi:10.1021/jp712025q

Cited by 90 publications

(120 citation statements)

References 46 publications

Supporting

Mentioning

117

Contrasting

Order By: Relevance

“…We have developed the nanocapsule method to prepare monodisperse Pt alloy nanoparticles uniformly dispersed on carbon supports with well-controlled composition. [9][10][11] For example, the kinetically-controlled mass activity MA k of a carbon-supported Pt 3 Co (atomic ratio) catalyst at 30 to 70°C was found to be 3.3 time higher than that of commercial carbon-supported Pt catalyst (c-Pt/C). 11 However, the durability of our Pt 3 Co/C catalyst was insufficient, since the dealloying of Co was not fully suppressed at high temperatures > 80°C, with the catalyst gradually becoming deactivated so that the MA k value was finally comparable to that of c-Pt/C.…”

Section: ¹1mentioning

confidence: 99%

“…[9][10][11] For example, the kinetically-controlled mass activity MA k of a carbon-supported Pt 3 Co (atomic ratio) catalyst at 30 to 70°C was found to be 3.3 time higher than that of commercial carbon-supported Pt catalyst (c-Pt/C). 11 However, the durability of our Pt 3 Co/C catalyst was insufficient, since the dealloying of Co was not fully suppressed at high temperatures > 80°C, with the catalyst gradually becoming deactivated so that the MA k value was finally comparable to that of c-Pt/C. Besides the degradation of the catalytic activity, the accompanying dissolution of nonprecious metal components must be avoided, because protons in the polymer electrolyte membrane and the electrolyte binder (ionomer) in the CL could be easily exchanged with the metal cations, inducing two types of serious damage as follows.…”

Section: ¹1mentioning

confidence: 99%

“…First, Pt-M alloy (1:1 atomic ratio) nanoparticles were highly dispersed on the support (denoted as Pt-M/C) by the nanocapsule method. 11 The projected total metal loading was 30 wt% for all samples. The Pt-M/C was heat-treated in 5% H 2 (N 2 balance) to segregate the Pt atoms on the surface.…”

Section: ¹1mentioning

confidence: 99%

“…11 The working electrode was Nafion μ -coated Pt 2AL -Pt-M/C uniformly dispersed on an Au substrate (geometric area 0.04 cm 2 ), which was prepared in the similar manner as that described in our previous work. 11,18 The amount of each catalyst was maintained at a constant loading of carbon support at 15 µg carbon cm ¹2 (corresponding to an approximately three-layer height of carbon particles 18 ), and the average thickness of Nafion μ was 0.1 µm. The ORR activities of the commercial Pt catalyst supported on carbon black (TEC10E50E, 50 wt%-Pt, specific surface area of the carbon support = ca.…”

Section: Characterization and Electrochemical Measurement Ofmentioning

confidence: 99%

See 3 more Smart Citations

Oxygen Reduction Reaction Activity of Carbon-Supported Pt-Fe, Pt-Co, and Pt-Ni Alloys with Stabilized Pt-Skin Layers

et al. 2016

Self Cite

View full text Add to dashboard Cite

We have prepared carbon-supported Pt-M (M = Fe, Co, and Ni) alloy nanoparticles with uniform size and composition as cathode catalysts for polymer electrolyte fuel cells. In order to protect the underlying Pt-M alloy from dealloying and maintain high mass activity for the oxygen reduction reaction (ORR), two atomic layers of Ptskin (Pt 2AL ) were formed on the Pt-M nanopartcicles. By means of various types of analysis, including X-ray diffraction (XRD), inductively coupled plasma mass analysis (ICP-MS), thermogravimetry (TG), and transmission electron microscopy (TEM), the formation of monodisperse Pt 2AL -Pt-M/C was confirmed. The kinetically-controlled ORR activities (mass activity, MA k , and area-specific activity, j k ) for the ORR at Nafion ® -coated Pt 2AL -Pt-M/C catalysts in O 2 -saturated 0.1 M HClO 4 solution were evaluated by the use of a multi-channel flow double electrode cell at 65°C. It was found that the initial value of MA k at Pt 2AL -PtNi/C was the highest, i.e., 3.3 times higher than that at a commercial catalyst, carbon-supported Pt (c-Pt/C). In contrast, the Pt 2AL -PtCo/C catalyst exhibited superior durability, so that dealloying was almost entirely suppressed, together with a great mitigation of the particle agglomeration after applying 10 4 cycles of potential steps between 0.6 V and 1.0 V.

show abstract

Section: ¹1mentioning

confidence: 99%

Section: ¹1mentioning

confidence: 99%

Section: ¹1mentioning

confidence: 99%

Section: Characterization and Electrochemical Measurement Ofmentioning

confidence: 99%

See 2 more Smart Citations

Oxygen Reduction Reaction Activity of Carbon-Supported Pt-Fe, Pt-Co, and Pt-Ni Alloys with Stabilized Pt-Skin Layers

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Pt nanoparticles produced using the nanocapsule method have been reported to be relatively small in particle size, and the size distribution can be relatively narrow. 21,27 Even using a modified method in this study, small Pt nanoparticles were successfully deposited on the BDDP surface. Pt/BDDP was also prepared using the nanocapsule method under the same conditions with BDDP-200.…”

Section: Resultsmentioning

confidence: 99%

Boron-Doped Diamond Powder as a Durable Support for Platinum-Based Cathode Catalysts in Polymer Electrolyte Fuel Cells

Kondo

Kikuchi

Masuda

et al. 2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

Platinum nanoparticle-supported boron-doped diamond powder (Pt/BDDP) was prepared and investigated as a durable polymer electrolyte fuel cell (PEFC) cathode catalyst. The use of the nanocapsule method enabled dense deposition of Pt nanoparticles (2-5 nm in size) on a boron-doped diamond (BDD) powder <500 nm in size. The Pt/BDDP cathode catalyst showed oxygen reduction reaction activity comparable to Pt-supported carbon black (Pt/C), indicating sufficient conductivity of the BDDP as a catalyst support. Potential cycling in a highly positive potential region (+1.0-+1.5 V vs. NHE) that simulates the start-stop operations of the PEFC was performed to investigate the durability of the Pt/BDDP catalyst. Decreases in the electrochemically active surface area of the Pt/BDDP were suppressed compared to that of Pt/C. Corrosion resistance of BDD against potential cycling was demonstrated by testing a BDD thin-film electrode. The corrosion resistance should be responsible for the improved durability of the BDDP support, possibly by lowering the Pt nanoparticle association process (e.g., agglomeration The polymer electrolyte fuel cell (PEFC) is a promising power generating system for portable devices, electric vehicles, and electric transportation applications because of its low operating temperature, high power density, high theoretical energy efficiency, and fast start-up advantages. 1,2 Improvement of PEFC durability has been desired for large-scale commercialization; a major obstacle is the deterioration of the carbon support for PEFC cathode catalysts. In frequent start-stop operations, particularly for automobiles, the cathode is exposed to a highly positive potential and the carbon support can be corroded via oxidation. 1,3-6 As solutions to this durability issue, SnO 2 , Nb-SnO 2 , 7 TiO x and TiN, 8 and polymer-coated carbon nanotubes 9 have all been reported as candidates for alternative support materials with superior tolerance to corrosion from electrochemical oxidation. Boron-doped diamond (BDD) has also attracted attention as an electrode material because it possesses excellent chemical/electrochemical stability. The BDD electrode is corrosion resistant; even in electrolytic water treatment at highly positive potentials, BDD electrode exhibits long service lifetimes with stable high performance. [10][11][12][13] To apply BDD as a PEFC catalyst support, BDD powder (BDDP) should be used. Several reports exist on the application of BDDP as a catalyst support for the direct methanol fuel cell anode catalyst. The Pt or Pt-Ru particle catalysts were deposited onto BDDP, and the catalysts exhibited high activity and stability to anodic methanol oxidation. [14][15][16][17][18] Recently, Kim reported that Pt/BDDP can be useful as a durable cathode catalyst for PEFC. 19 They fabricated a unit cell using the Pt/BDDP cathode catalyst and found that the decrease in Pt loading during an accelerated long-term test (0.6 V at 90 • C) was less on the BDD support than on the Vulcan XC-72 or multi-walled carbon nanotube supports. ...

show abstract

Electrocatalysis at Platinum and Bimetallic Alloys

Watanabe¹,

Uchida²

2008

Fuel Cell Catalysis

Self Cite

View full text Add to dashboard Cite

Temperature Dependence of Oxygen Reduction Activity at Carbon-Supported Pt_XCo (X = 1, 2, and 3) Alloy Catalysts Prepared by the Nanocapsule Method

Cited by 90 publications

References 46 publications

Oxygen Reduction Reaction Activity of Carbon-Supported Pt-Fe, Pt-Co, and Pt-Ni Alloys with Stabilized Pt-Skin Layers

Oxygen Reduction Reaction Activity of Carbon-Supported Pt-Fe, Pt-Co, and Pt-Ni Alloys with Stabilized Pt-Skin Layers

Boron-Doped Diamond Powder as a Durable Support for Platinum-Based Cathode Catalysts in Polymer Electrolyte Fuel Cells

Electrocatalysis at Platinum and Bimetallic Alloys

Contact Info

Product

Resources

About