Supplementary Information
Selective electrocatalysts toward a prototype
of the
membraneless direct methanol fuel cell
Yan Feng,1,2 Jinhua Yang,3 Hui Liu,1,2 Feng Ye,1 Jun Yang1,3,*
1State
Key Laboratory of Multiphase Complex Systems, Institute of Process
Engineering, Chinese Academy of Sciences, Beijing, China 100190. Fax: 86-10-8254
4915; Tel: 86-10-8254 4915; E-mail: jyang@mail.ipe.ac.cn
2University
of Chinese Academy of Scieneces, No. 19A Yuquan Road, Beijing, China
100190
3Institute
of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, 04-01,
Singapore 138669
Financial support from the 100 Talents Program of the Chinese Academy of Sciences,
National Natural Science Foundation of China (No.: 21173226, 21376247), State Key
Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese
Academy of Sciences (MPCS-2012-A-11, MPCS-2011-D-08, MPCS-2010-C-02), and the
Institute of Bioengineering and Nanotechnology (Biomedical Research Council,
Agency for Science, Technology and Research, Singapore) is gratefully acknowledged.
S1
(a)
(b)
10 nm
2 nm
(c)
(d)
10 nm
2 nm
(e)
(f)
Counts (a.u.)
Cu
C
Cu
Cu
Au
Ag
S
Au
10 nm
0
5
10
Au
Ag
15
Energy (keV)
20
25
Figure S1 | Au seeds and core-shell Au@Ag2S intermediates. TEM image (a) and HRTEM image
(b) of Au seed nanoparticles synthesized by NaBH4 reduction of HAuCl4 in aqueous phase; TEM
image (c), HRTEM image (d), STEM image (e), and EDX spectrum (f) of the core-shell Au@Ag2S
nanocrystals used for the fabrication of ternary Au@Ag2S-Pt nanocomposites.
S2
0.6
Au@Ag2S-Pt
E-TEK Pt/C
0.5
jnorm
0.4
0.3
0.2
0.1
0.0
0
3000
6000
9000
12000
t (s)
Figure S2 | Stability of Au@Ag2S-Pt nanocomposites and commercial Pt/C catalysts for MOR.
chronoamperograms of ternary Au@Ag2S-Pt nanocomposites and commercial Pt/C at 0.45 V in
argon-purged HClO4 (0.1 M) with methanol of 1 M.
(a)
10 nm
(b)
(c)
1 nm
(f)
1 nm
(g)
(h)
Intensity (a.u.)
(e)
10 nm
(d)
10 nm
10 nm
2 nm
Ru
Ag
Pt
0
4
8
12
Position (nm)
16
20
Figure S3 | Pt seeds, core-shell Pt@Ag, and core-shell-shell Pt@Ag@Ru nanoparticles. TEM
image (a) and HRTEM image (b) of Pt seed nanoparticles synthesized in oleylamine at elevated
temperature; TEM image (c) and HRTEM image (d) of core-shell Pt@Ag nanoparticles synthesized
in oleylamine at elevated temeprature; TEM image (c), HRTEM image (d), STEM image (e), and
EDX-based line scanning analysis (f) of the core-shell-shell Pt@Ag@Ru nanoparticles used for the
fabrication of CBS Pt-Ru nanoparticles.
S3
Table S1 | Electrochemical measurements of methanol oxidation on ternary Au@Ag2S-Pt
nanocomposites and commercial Pt/C catalysts. The results were obtained from Figure 2e.
Material
Forward Scan
Forward Scan Peak
Backward Scan
Backward Scan Peak
Peak Potential
Current Density
Peak Potential
Current Density
(V)
(mAcm-2)
(V)
(mAcm-2)
Au@Ag2S-Pt
0.60
137.6
0.46
100.3
Pt/C
0.64
67.3
0.52
48.5
Table S2 | Comparison of the catalytic activity of ternary Au@Ag2S-Pt nanocomposites and
commercial Pt/C catalysts for the reduction of O2 at room temperature. The data were obtained
from Figure S2f.
Material
Half-Wave Potential at 1600
Kinetic Current Density at Half-Wave
rpm (V)
Potential (mAcm-2)
Au@Ag2S-Pt
0.48
0.75
Pt/C
0.62
2.85
S4