abstract - 國立臺灣大學rsliu/poster/2013/syuanhong-ms... · 2014-06-23 · 0.30 0.45 0.60...
TRANSCRIPT
0.30 0.45 0.60 0.75 0.90 1.05 1.20-5
-4
-3
-2
-1
0
Cu
rren
t d
ensi
ty (
mA
cm
-2)
Potential (V vs. RHE)
20 w.t. % Pt/C
FePtN/C-700oC-acid
FePtN/C-650oC-acid
FePtN/C-600oC-acid
10 20 30 40 50 60 70 80
No
rm
ali
zed
in
ten
sity
(a
.u.)
FePtN-2hr-500oC
FePtN-2hr-550oC
FePtN-2hr-600oC
FePtN-2hr-650oC
(111)
FePtN-2hr-700oC
(110)
(001)
(002)
(011)
(002)
(110)
(011)
Fe3PtN-ICSD-44864
Fe2N-ICSD-20390
(020)
(002)
(111)
(001)
2Theta (degree)
FePt-ICSD-659004
Nitrogen containing FePt Catalyst in Oxygen
Reduction Reaction for Fuel Cells
Syuan-Hong Chen (陳宣宏) and Ru-Shi Liu* (劉如熹)
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
Abstract
To promote the commercial of fuel cell, designing a High activity, high stability and low cost catalyst was a critical issue. Recently, the catalyst which
iron nitride nanoparticle deposited on the zero dimensional and three dimensional carbon support was synthesized under the ammonia atmosphere and
demonstrated a well performance in activity, electron transfer and yield of hydrogen peroxide in oxygen reduction reaction. However, its activity was still
lower than commercial Platinum catalyst.
The electronic structure was an important factor to enhance the activity and inhabit the side reaction of catalyst. In present study, we established
method to improve the activity by importing an electron donor, platinum for example, into the iron nitride catalyst enhance the back donation of active site.
In the present study, the characteristics of catalyst were identified by following technology. Crystal structure identified X-ray powder diffraction. X-
ray absorption spectroscopy by using synchrotron radiation was applied for oxidation number of iron and platinum. The oxygen reduction performance
was identified by cyclic voltammery. Confirm the introduction of platinum into iron nitride catalyst would enhance the catalytic activity.
Results
Approaching Method
Provide a low d-band vacancy element to promote backdonation of oxygen reduction reaction: enhance the activity of reaction
X-ray Absorption Spectroscopy for
Electronic structure Characterization
Transmission Electron Microscopy
Introduction
XRD Pattern of Different Synthesis Method
Conclusions
Oxygen Reduction Reaction Performance
:Pt :Fe :N
Fe2N, trigonal Fe3PtN, cubic
Pt4+
NH3(g)
0.0 0.2 0.4 0.6 0.8 1.0 1.2-6
-5
-4
-3
-2
-1
0
Cu
rren
t d
en
sity
(m
A c
m-2
)
Potential (V vs. RHE)
20 wt. % Pt/C
FeN/C
10 20 30 40 50 60 70 80
No
rm
ali
zed
in
ten
sity
(a
.u.)
FePtN/C-600oC-acid
FePtN/C-650oC-acid
FePtN/C-700oC-acid
Fe3PtN-ICSD-44864
(002)
(110)
(011)
(111)
(001)
(002)
(011)
2Theta (degree)
Fe2N-ICSD-20390
7050 7100 7150 7200 7250 7300
Energy (eV)
Norm
ali
zed
In
ten
sity
Fe foil
FeAc2
FeN/C
FePtN/C
11550 11560 11570 11580 11590 11600
Norm
ali
zed
In
ten
sity
Energy (eV)
Pt foil
PtO2
Fe3PtN/C-acid
7112 7116 7120 7124 7128
Norm
ali
zed
In
ten
sity
(001)
(111)
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2-5
-4
-3
-2
-1
0
Cu
rren
t d
ensi
ty (
mA
cm
-2)
Potential (V vs. RHE)
20 w.t.% Pt/C
FePtN/C
FeN/C
0.0 0.2 0.4 0.6 0.82
3
4
0
25
50
75
100
Potential (V vs. RHE)
20 w.t. % Pt
FePtN/C-700oC
FePtN/C-650oC
FePtN/C-600oC
H2O
2 y
ield
(%
)
Ele
ctr
on
nu
mb
er
Electron transfer and H2O2 yeild
The activity of iron nitride catalyst improved by importing
platinum as an electron donor. The oxidation states from XANES
conform the electron transfer between iron and platinum.
Ref: J. Electrochem. Soc. 1999, 146, 3750. Ref: Adv. Catal. 2000, 45, 71.