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Synthesis and Characterization of a trimetal catalyst used for the water electrolyzer
and fuel cell
STUT, Mechanical Engineering
SPEACH : En-Xian Lin
Student ID: M991A203
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Outline
 Introduction
 Expermental


Catalysts fabrication
Membrane electrode assembly (MEA) prepartoin & Single Cell Device
 Result and discussion
 Conclusion
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Introduction
 Fuel cell applications is very wide, power generation can be divided
into three categories according to:
 Portable electronic products, all kinds of transport, set-type generator
2005年
元智大學燃料電池國際研討會漢
氫科技(股)公司 展示一個筆記型
電腦燃料電池內鍵卡匣式儲氫器
圖片來源：台灣經濟研究院
ZESIV.5
圖片來源：亞太燃料電池(股)公司
1kW可攜式燃料電池緊急發電機
圖片來源：
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工業技術研究院
能源與 環境研究所
What is the URFC?
PEMFC
+
SPE
URFC
 The mid-1980s, the development of Solid Polymer Electrolyte (SPE), up to
70 ~ 80% efficiency, output high-purity hydrogen and oxygen. This system can
match with the Proton exchange membrane fuel cell (PEMFC) system, due to
the use of components does not differ greatly between the two, each chemical
reaction is the reverse reaction, combined this two device can be achieved simply
by changing the mode of operation of power generation and hydrogen production
capabilities, is the single Unitized Regenerative Fuel Cell (URFC).
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Anode electrocatalysts
Cathode electrocatalysts
Pt–Ir
Pt/C
Pt–Ru–Ir
Pt-Ru/C
Pt–IrO2
Pt-Ru-HxWO3/C
Pt–IrO2–RuO2
Table 2 . Common and applicable to URFC catalyst.
 Platinum (Pt) is often used in various types of fuel cells ,
such as AFC, PAFC, PEMFC, etc. ..., because there is good
for hydrogen adsorption capacity, it was one of fuel cell
catalysts options..
 However, the effect of carbon with water molecules in the
water electrolysis, when the supply voltage increase than
0.118V it will be generates CO2 to Corrosion the plate.
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URFC(Unitized
Regenerative Fuel Cell)
 URFC(Unitized Regenerative
Fuel Cell)
 Water electrolyzer Mode
 Fuel Cell Mode
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Expermental
Single Cell Assembly
 As shown, a single cell from the inside
out in order of MEA, the diffusion layer,
sealing gasket, flow field plates,
electrodes, plate combination.
 Most of the diffusion layer with low
porosity and drainage of carbon cloth
(paper).
 Flow field plates are generally used
carbon plate, metal plate or composite
graphite fibers.
 As URFC functions must perform water
electrolysis, so the experimental use of
titanium metal plate as a flow field plate.
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Preparation of reversible membrane electrode assemblies
 Typical metal loadings of 0.7 and 2.4 mg/cm−2 were obtained for
cathodes and anodes, respectively. Finally, membrane-electrode
assemblies (MEAs) were prepared by hot pressing the Ti-supported
electrocatalytic layers against each side of the Nafion ® membrane
1. Resistance to chemical corrosion.
2. Operating temperature up to 190 ℃.
3. High ionic conductivity.
4. Sulfonic acid has a strong function of proton exchange.
5. Nafion has very selective and high permeability of water.
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Schematic diagram of MEA Process
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Tri-catalysts processes
Chloroplatinic acid
 We have two sample of
catalysts .
 Sample A: Without IPA
 Sample B: With IPA
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Result and discussion
 Black titanium can be used as catalyst
carrier, if the beginning of serious
agglomeration area will result in
reduction of its activity.
 Sample A was serious accumulative,
cause specific surface area decreased.
 Sample B after adding IPA slow agglomeration.
Fig. 1 The TEM image of
Sample A (a)di-metal Pt-IrO2 (b)tri-metal PtIrO2/Ti
Sample B (c) di-metal(d) tri-metal
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Electrochemical analysis
Fig. 2 Cyclic voltammetry at room temperature
and at a sweep rate of 20 mV-1 for the
electrolyzer equipped with Pt-IrO2 and PtIrO2/Ti .
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 For the particles described in
Fig. 1 are shown in Fig . 2
 The hydrogen desorption and
adsorption reaction of the PtIrO2 sample occurred on
potential between 0.2V-0.8V.
 The characteristic potential of
the Pt-IrO2/Ti is better than PtIrO2 which implies that the
activity Pt-IrO2/Ti is better than
Pt-IrO2.
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a
 Fig 3. Shown in AC impendence of
Pt-IrO2 and Pt-IrO2/Ti catalysts with
or without the addition of IPA. The
resistance of the tri-metal catalyst is
lower than that of di-metal catalyst,
the Rct value of tri-metal and di-metal
catalysts is 1.4 and 0.8 respectively.
Fig. 3.AC impendence of catalysts (a)
without IPA and (b) with IPA
addition. 。
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Single Cell Test
 Performance indicators:
 Voltage Efficiency:
v 
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1.48V
measured cell voltage
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Water Electrolysis Test
 The operation voltage of water
electrolysis was about 1.5V~1.6V
 Fig .4 shows the water electrolysis
performance of Pt-IrO2/Ti in
different IPA concentration in the
current density of 100mA/cm2.
The voltage efficiency of ratio
IPA:DI water=1:1 ,2:1 was 32.8%
and 42.2% , respectively.
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Conclusions
 In this study, di-metals Pt-IrO2 and tri-metals Pt-IrO2/Ti catalysts
were prepared by spontaneous deposition.
 The Pt coated on the IrO2 particle tightly and Ti-black supported PtIrO2 catalyst has larger active area and better water electrolysis
efficiency.
 Higher IPA concentration can dispersed the composite particle well.
 From water electrolysis performance tests obtained with the
addition of IPA to reduce the catalyst agglomeration,
significantly improved catalyst utilization, so the efficiency
of water electrolysis voltage difference between two samples of
about 10%.
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謝謝聆聽
Thank you for your
attention !
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