Supporting Information
Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2014
A Highly Stable and Active Hybrid Cathode for LowTemperature Solid Oxide Fuel Cells
Fengli Liang, Wei Zhou,* and Zhonghua Zhu*[a]
celc_201402143_sm_miscellaneous_information.pdf
Supporting Information
Figure S1. XPS of Ag@CeO2 core-shell spheres powder. The XPS signals of Ag 3d appear
at a binding energy of 368.2 and 374.2 eV, which should be assigned to the binding energies
of Ag 3d5/2 and Ag 3d3/2 of the metallic nature Ag0 of the silver core in the Ag@CeO2 coreshell spheres.
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Figure S2. TEM shows the Ag core size is between 50 to 80 nm and CeO2 shell with a
uniform thickness of 20-30 nm. The Ag@CeO2 core-shell spheres were treated in diluted
HNO3 for 5 min to expose the Ag cores.
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Figure S3. Pore size distribution curves of Ag@CeO2 core-shell spheres powder.
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Figure S4. Raman spectra of CeO2 in Ag@CeO2 and CeO2 prepared by co-precipitation. The
Ag@CeO2 spheres were treated in 6M HNO3 to remove Ag leaving CeO2 for Raman test.
The CeO2 powders prepared by co-precipitation were also treated in 6M HNO3 to rule out the
possible effect from HNO3. The CeO2 in Ag@CeO2 shows additional peak at around 560 cm1
, which is indicative of the creation of massive number of oxygen vacancies. [1-3]
[1] Taniguchi, T.; Watanabe, T.; Sugiyama, N.; Subramani, A. K.; Wagata,H.; Matsushita, N.;
Yoshimura, M. J. Phys. Chem. C 2009, 113 (46), 19789-19793.
[2] Nakajima, A.; Yoshihara, A.; Ishigame, M. Phys. Rev. B 1994, 50 (18), 13297-13307.
[3] Wu, Z.L.; Li, M.J.; Howe, J.; Meyer, H.M.; Overbury, S.H. Langmuir 2010, 26(21),
16595–16606.
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Figure S5. The TEM images of (a) CeO2 in Ag@CeO2 and (b) CeO2 prepared by coprecipitation. The circles in (a) mark some of oxygen vacancy clusters. Perfect lattice was
observed in CeO2 prepared by co-precipitation, while CeO2 in Ag@CeO2 shows many
oxygen vacancy clusters. It has been reported that the oxygen vacancy clusters can promote
the reducibility and activity of ceria. [4]
[4] Liu, X.W.; Zhou, K.B.; Wang, L.; Wang, B.Y.; Li, Y.D. J. Am. Chem. Soc. 2009, 131,
3140–3141.
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Figure S6. SEM images of Ag decorated SSNC cathode before a) and after b) exposed to
operation conditions for 24 hours. The initial Ag particles are 40-100 nm prepared using the
conventional wet infiltration at 500 oC; however, the Ag particles grew up into coarse
particles (200-400 nm) at 650oC for only 24 hours.
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Figure S7. The Arrhenius plots of RE1 and RE2 for the pristine SSNC and Ag@CeO2
decorated SSNC cathodes measured between 450 to 650 °C.
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Figure S8. SEM image for pure CeO2 decorated SSNC cathode. The particle size of CeO2 is
about 120 nm for the CeO2 decorated cathode which is similar to that of Ag@CeO2. The
CeO2 particles were prepared by removing Ag from Ag@CeO2 using HNO3.
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Figure S9. The Arrhenius plot of the Ag decorated SSNC cathode. The Activation energy of
ORR on the Ag decorated SSNC cathode is 105 kJ mol-1 in the temperature range between
450 and 650 ºC. The ASR value of the cathode at 500 ºC is 0.294 Ω cm2.
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Figure S10. The Arrhenius plots of the CeO2 decorated SSNC cathode. The Activation
energy of ORR on the Ag decorated SSNC cathode is 109 kJ mol-1 in the temperature range
of 450 and 650 ºC. The ASR value of the cathode at 500 ºC is 0.376 Ω cm2.
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