Download Effects of antioxidants for the degradation of flame

原稿見本
1 - 24
論文番号（記載不要）
Arial：14 Pt, Bold
上余白:25 mm
英語版
Nitrogen Doping in Carbon-Based Cathode Catalysts
大文字
Using Electron Beam Process
右ｲﾝﾃﾞﾝﾄ幅:12 mm
12 Pt
M.
T.
S.
H. Pt
T.
and T. Hagiwara b)
Arial：11
左ｲﾝﾃﾞﾝﾄ幅:8mm
右ｲﾝﾃﾞﾝﾄ幅:8mm
a) Department of Advanced Functional Materials Research, TARRI, QST,
12 Pt
Arial：11 Pt b) Faculty
of Engineering, Saitama Institute of Technology
字下げ：
4 mm Nitrogen-doped (N-doped) carbon-based catalysts中央段間隔:
for
through thermally non-equilibrated reactions during the EB
7.5 mm
oxygen reduction reactions (ORRs) are expected as
irradiation.
左ｲﾝﾃﾞﾝﾄ幅:23 mm
Sugimoto a),
Ohta b),
Yamamoto a),
Koshikawa a),
Yamaki a)
ORR potential
vs. RHE (V)
Intensity (arb. units)
Arial：9 Pt
platinum-alternative material [1]. It has been predicted that
Bold
the ORR activity should be related to the chemical states
References
行間：固定値 12 Pt
of N atoms doped in graphite. However, no one has so far
[1] J. Ozaki et al., Carbon, 44, 1298-352 (2006).
established a method for introducing the N-related active
[2] K. Lee et al., Electrochim. Acta, 49, 3479-85 (2004).
sites reproducibly and quantitatively because there is a
[3] J.-H. Kim et al., Electrochim. Acta, 52, 2492-97 (2007).
difficulty in controlling the atomic concentration of N and
ぶら下げ：5 mm
the graphite structures independently. We prepared
N-doped carbons by heating aromatic polymer precursors
Table 1
テキストボックスの
in an ammonia (NH3) atmosphere under electron-beam
Conditions of our sample preparation.
推奨横幅：82.2 mm
(EB) irradiation and then examined the irradiation effect on
Sample CoCl2 (wt%)
Doping Method
Carbonization
the doping and ORR装置・施設、放射線
properties in terms of thermally
(a)
0
500 °C in 0.1% NH3
non-equilibrated kinetics.の種類等の記載
without EB
(b)
5
800 °C
A precursor was phenolic resin (Gunei Chemical,
in N2
(c)
0
500 °C in 0.1% NH3
PSK-2320) or its mixture with 5 wt% cobalt(II) chloride
with 2 MeV EB
(d)
5
右余白:
左余白: (CoCl2). It was irradiated with 2 MeV EB at a dose of up to
19 mm
19 mm 6 MGy in 0.1 vol% NH3 at 500 °C. The irradiated powder
N/C ratio
was then subjected to carbonization at 800 °C for 1 h in Ar.
N 1s
(atomic%)
The synthesis conditions are summarized in Table 1. The
resulting samples were analyzed by transmission electron
(d) 0.51
microscopy (TEM) and X-ray photoelectron spectroscopy
(c) 0.49
(XPS). The electrocatalytic activity was tested by linear
sweep voltammetry with a rotating disk electrode (RDE).
(b) 0.27
「標準の文字数を使う」
The catalyst powder
acid-washed to remove the Co
species was dispersedArial：9
in a mixture
(a) 0.28
Pt with a Nafion solution
and then coated行間：固定値
on the surface
of
a
glassy
carbon
12 Pt
410
405
400
395
390
electrode. The measurements were performed in a 0.1 M
Binding energy (eV)
aqueous perchloric acid solution. The ORR activity was
determined from voltammograms in a manner similar to
that reported elsewhere [2, 3], where the electrolyte was
Fig. 1. N 1s XPS spectra of samples (a) to (d) and N/C ratios
saturated with O2 or N2 gas.
estimated byArial：8
these data.Pt（1 行の場合は中央揃え）
Samples (b) and (d) comprised a graphite phase while
samples (a) and (c) were amorphous. This result suggests
an important role of CoCl2 in the formation of crystalline
1.0
structures. Figure 1 shows N 1s XPS spectra, enabling us
テキストボックスの
to confirm the existence of N dopants. As a whole, the
0.8 推奨横幅：82.2 mm
samples prepared by the EB irradiation exhibited a high N
concentration; therefore, the EB-induced non-equilibrated
0.6
process would activate the N-doping reactions. A doping
0.4
level reached an atomic concentration of nitrogen about
0.5% when 5 wt% CoCl2 was mixed in the precursor
0.2
(sample (d)).
Figure 2 shows the ORR potential as an indicator of the
0
activity. Strikingly, sample (d) exhibited a potential of
(a) (b) (c) (d) Pt
0.93 V versus a reversible hydrogen electrode (RHE),
which is comparable to that of a Pt standard sample
Fig. 2. ORR potential vs. RHE of samples (a) to (d) and the Pt
(1.05 V). In conclusion, we were able to present the
standard sample.
Arial：8 Pt（1 行の場合は中央揃え）
possibility of developing the carbon-based ORR catalysts
下余白:25 mm
Template
分類番号
1 - 24
1
カラー印刷希望
無
課題（整理）番号
使用施設・加速器
A-06
E
Nitrogen Doping in Carbon-Based Cathode Catalysts
Using Electron Beam Process
M. Sugimoto a), T. Ohta b), S. Yamamoto a), H. Koshikawa a), T. Yamaki a) and T. Hagiwara b)
a) Department
of Advanced Functional Materials Research, TARRI, QST,
Faculty of Engineering, Saitama Institute of Technology
through thermally non-equilibrated reactions during the EB
irradiation.
References
[1] J. Ozaki et al., Carbon, 44, 1298-352 (2006).
[2] K. Lee et al., Electrochim. Acta, 49, 3479-85 (2004).
[3] J.-H. Kim et al., Electrochim. Acta, 52, 2492-97 (2007).
Table 1
Conditions of our sample preparation.
Sample
(a)
(b)
(c)
(d)
CoCl2 (wt%)
0
5
0
5
Intensity (arb. units)
Nitrogen-doped (N-doped) carbon-based catalysts for
oxygen reduction reactions (ORRs) are expected as
platinum-alternative material [1]. It has been predicted that
the ORR activity should be related to the chemical states
of N atoms doped in graphite. However, no one has so far
established a method for introducing the N-related active
sites reproducibly and quantitatively because there is a
difficulty in controlling the atomic concentration of N and
the graphite structures independently. We prepared
N-doped carbons by heating aromatic polymer precursors
in an ammonia (NH3) atmosphere under electron-beam
(EB) irradiation and then examined the irradiation effect on
the doping and ORR properties in terms of thermally
non-equilibrated kinetics.
A precursor was phenolic resin (Gunei Chemical,
PSK-2320) or its mixture with 5 wt% cobalt(II) chloride
(CoCl2). It was irradiated with 2 MeV EB at a dose of up to
6 MGy in 0.1 vol% NH3 at 500 °C. The irradiated powder
was then subjected to carbonization at 800 °C for 1 h in Ar.
The synthesis conditions are summarized in Table 1. The
resulting samples were analyzed by transmission electron
microscopy (TEM) and X-ray photoelectron spectroscopy
(XPS). The electrocatalytic activity was tested by linear
sweep voltammetry with a rotating disk electrode (RDE).
The catalyst powder acid-washed to remove the Co
species was dispersed in a mixture with a Nafion solution
and then coated on the surface of a glassy carbon
electrode. The measurements were performed in a 0.1 M
aqueous perchloric acid solution. The ORR activity was
determined from voltammograms in a manner similar to
that reported elsewhere [2, 3], where the electrolyte was
saturated with O2 or N2 gas.
Samples (b) and (d) comprised a graphite phase while
samples (a) and (c) were amorphous. This result suggests
an important role of CoCl2 in the formation of crystalline
structures. Figure 1 shows N 1s XPS spectra, enabling us
to confirm the existence of N dopants. As a whole, the
samples prepared by the EB irradiation exhibited a high N
concentration; therefore, the EB-induced non-equilibrated
process would activate the N-doping reactions. A doping
level reached an atomic concentration of nitrogen about
0.5% when 5 wt% CoCl2 was mixed in the precursor
(sample (d)).
Figure 2 shows the ORR potential as an indicator of the
activity. Strikingly, sample (d) exhibited a potential of
0.93 V versus a reversible hydrogen electrode (RHE),
which is comparable to that of a Pt standard sample
(1.05 V). In conclusion, we were able to present the
possibility of developing the carbon-based ORR catalysts
Doping Method
500 °C in 0.1% NH3
without EB
500 °C in 0.1% NH3
with 2 MeV EB
Carbonization
800 °C
in N2
N/C ratio
(atomic%)
N 1s
410
405
400
395
(d)
0.51
(c)
0.49
(b)
0.27
(a)
0.28
390
Binding energy (eV)
Fig. 1. N 1s XPS spectra of samples (a) to (d) and N/C ratios
estimated by these data.
ORR potential
vs. RHE (V)
b)
1.0
0.8
0.6
0.4
0.2
0
(a)
(b) (c)
(d)
Pt
Fig. 2. ORR potential vs. RHE of samples (a) to (d) and the Pt
standard sample.