1 Speaker: Chun-Yang Hsieh Advisor : Wen-Chang Wu Date : 2015.04.08 Preparation and Characterization of Pt/SnO 2 /C Cathode Catalyst for Proton Exchange Membrane Fuel Cell (PEMFC)
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Speaker: Chun-Yang Hsieh
Advisor : Wen-Chang Wu
Date : 2015.04.08
Preparation and Characterization of Pt/SnO2/C Cathode Catalyst for Proton Exchange Membrane
Fuel Cell (PEMFC)
IntroductionReview of the Literature
Motivation
Experimental Method
Results and Discussion
Conclusions
Future Work
Outline
Introduction
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The fuel cell
High power generation efficiency
Wide range of applications
No chargeneeded
Wide fuel sources
Low pollution
Introduction
4
Portable electronic products
Transportation
Generator
Introduction
5
There are several different kinds of fuel cells .
Alkaline fuel cell (AFC)
Phosphoric acid fuel cells (PAFC)
Molten Carbonate Fuel Cell (MCFC)
Solid Oxide Fuel Cell (SOFC)
Proton Exchange Membrane Fuel Cell (PEMFC)
Direct methanol fuel cell (DMFC)
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Introduction
PEMFC
High mobility
High efficiency
Cryogenic quick start
Low pollution
Introduction
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Catalyst
Proton exchange membraneCatalyst
Introduction-CV
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Introduction
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Between Pt and SnO2 there is a strong interaction, this phenomenon is sometimes explained as strong metal–support interaction (SMSI).
This interaction can inhibit the Pt metal corrosion.
It has also been found that SMSI has an increase in activity for oxygen reduction effect.
The real mechanism of SMSI is not always clear for several catalyst systems.
Introduction
Review of the LiteratureMotivation
Experimental
Results and discussion
Conclusions
Future work
Outline
11
Review of the Literature
The SiO2/Pt/C catalyst exhibited higher durability than the Pt/C one, due to the facts that the silica layers covered were beneficial for reducing the Pt aggregation and dissolution as well as increasing the corrosion resistance of supports.
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Review of the Literature
Pt/SnO2 shows the best performance in terms of both electrochemical activity, and stability against dissolution. Pt dissolution rates in Pt/SnO2 are comparable to those of conventionalPt/C electrocatalysts.
Introduction
Review of the Literature
MotivationExperimental
Results and discussion
Conclusions
Future work
Outline
Motivation
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The life span of the Pt catalyst is reduced because of CO poisoning, Pt dissolution and carbon corrosion of the support substrate.
The literature indicates oxide can improve the durability of TiO2, Ti0.7W0.3O2, and CeOx between others.
The higher electrochemical stability with SnO2 can be attributed to the strong interaction between the Pt and SnO2.
Motivation
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This study strives to add the SnO2 to increase the cathode catalyst activity and durability,and to assess the analysis to explore different SnO2 / C composition ratio and other parameters the catalytic activity and electrochemical stability.
Introduction
Review of the Literature
Motivation
Experimental Method Results and discussion
Conclusions
Future work
Outline
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SnCl4 nH‧ 2O
NH4OH
Vulcan XC-72
H2PtCl6·(H2O)6
C6H8O7
NaBH4
Material
Fabrication of catalyst support
Vulcan carbon
distilled water and stirred for 30 min
SnCl4 5H‧ 2O
Tin oxide was formed upon precipitation
1M ammonium hydroxide
filtered, andthen washed copiously with
de-ionized water
stirred for 2 h
placed in an oven at 80 ◦C
calcination
SnO2/C
Fabrication of Pt supported over SnO2/C
Aqueous solution of hexachloroplatinic acid
stirred for 30 min
citric acid
stirred for 1 h
SnO2/C support
stirred continuously for 2 h
NaBH4
50mL de-ionizedwater
filtered, washed
placed in an oven at 80 ℃ to get the final product
Ultrasonic wave
filtered, washed
placed in an oven at 80 ℃ to get the final product
Pt/SnO2/C, Pt/C
Pt/SnO2/C, Pt/C
Introduction
Review of the Literature
Motivation
Experimental
Results and discussionConclusions
Future work
Outline
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Different pH
Fig.1.XRD of SnO2 (a) pH=2.0 (b) pH=4.0 (c) pH=8.0
(b)
(a)
(c)(110)
(101)(200)
(211)
(220) (310)(301)
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Different calcination temperature
Fig. 2. XRD patterns of SnO2 calcined at different temperatures ( a ) no calcined ( b ) 200℃ (1 deg/min).
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Fig. 3. XRD patterns of SnO2 calcined at different temperatures ( a ) 200℃ ( b ) 300℃ ( c ) 400℃ ( d )500℃ ( e ) 600℃ ( f ) 700℃ ( g ) 800℃ (4 deg/min).
Different calcination temperature
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Table.1. Effect of calcination temperature on grain size of SnO2.
Grain Size
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Fig. 4.TEM images of SnO2/C nanopowder calcined at different temperatures ( a ) 200℃ ( b ) 300℃ ( c ) 500℃( d ) 600℃ ( e ) 800℃.
TEM
17nm
7nm
26Fig. 5. XRD of Pt/C and Pt/SnO2/C catalysts.
XRD
(111) (200)(220)(002)
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Table.2. Grain size of Pt with different SnO2/C content .
Grain Size
Catalysts grain size of Pt (nm)
Pt/C 12.7
Pt/10SnO2/70C 10.2
Pt/20SnO2/60C 8.5
Pt/40SnO2/40C 7.7
Pt/60SnO2/20C 7.4
28Fig.6.TEM images of Pt/C and Pt/SnO2/C catalysts.
29Fig.7. TEM images of Pt/C and Pt/SnO2/C catalysts.
Ultrasonic wave
Ultrasonic wave
Pt/C
Pt/20 SnO2/60 C
Ultrasonic wave
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Fig 8. Cyclic voltammograms of Pt/C and Pt/SnO2/C in 0.5M H2SO4 solution at 50 mVs-1.
Electrochemical characterizations-0.2 ~ +0.2V
H2 desorption
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Table.3.The electrochemical surface area of Pt/C and Pt/SnO2/C
Electrochemical characterizations
Catalysts EAS (cm2/mg)
Pt/C 59
Pt/10SnO2/70C 102
Pt/20SnO2/60C 195
Pt/40SnO2/40C 228
Pt/60SnO2/20C 123
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Fig 7. With or without ultrasonic dispersion treatment of CV (a) Pt/C (b) Pt/10%SnO2/C (c) Pt/20%SnO2/C (d) Pt/40%SnO2/C (e) Pt/60%SnO2/C .
Electrochemical characterizations
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Table.4.The electrochemical surface area of Pt/C and Pt/SnO2/C
Electrochemical characterizations
Catalysts 無超音波之 EAS
(cm2/mg)
有超音波 之 EAS
(cm2/mg)
Pt/C 59 89
Pt/10 SnO2/70 C 102 121
Pt/20 SnO2/60 C 195 222
Pt/40 SnO2/40 C 228 253
Pt/60 SnO2/20 C 123 157
Introduction
Review of the Literature
Motivation
Experimental
Results and discussion
ConclusionsFuture work
Outline
Conclusions
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1. This study successfully used the precipitation method to prepare nano-tin dioxide powder.
2. Successfully used chemical reduction to prepared nanoscale Pt / SnO2 / C catalyst powder
3. By using ultrasonic dispersion treatment, better dispersibility of the Pt / SnO2 / C catalyst can be obtained in the preparation process
Conclusions
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4. Add a 40wt.% SnO2 of Pt / SnO2 / C catalysts to have a higher electrochemical active surface area, 228 cm2/mg than owned Pt / C catalyst.
5. The electrochemical active surface of the ultrasonic dispersion treatmented cathode catalyst is higher than without treatment, has the best EAS value of Pt / 40SnO2 / 40C for 228 cm2 / mg, after the ultrasonic treatment, EAS upgraded to 253 cm2 / mg.
Outline
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The durability test.
Membrane electrode assembly (MEA) test.
Future work
References
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Takeoh Okanishi, Toshiaki Matsui, Tatsuya Takeguchi ,Ryuji Kikuchi, Koichi Eguchi. Chemical interaction between Pt and SnO2 and influence on adsorptive properties of carbon monoxide. Applied Catalysis A: General 298 (2006) 181–187.
Y. Takabatake , Z. Noda , S.M. Lyth , A. Hayashi , K. Sasaki . Cycle durability of metal oxide supports for PEFC electrocatalysts. i n t e rna t i o n a l journa l o f hydrogen energy xxx ( 2 0 1 4 ) 1 -9.
衣寶廉,「燃料電池-原理與應用」,五南圖書出版股份有限公司,民 95年。 黃鎮江,「燃料電池」,全華科技圖書股份有限公司,民 92 年。
Thanks for your attention
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