TY - JOUR
T1 - Evaluating surface protonic transport on cerium oxide via electrochemical impedance spectroscopy measurement
AU - Manabe, Ryo
AU - Stub, Sindre Østby
AU - Norby, Truls
AU - Sekine, Yasushi
N1 - Funding Information:
R. M. acknowledges the Leading Graduate Program in Science and Engineering, Waseda University, supported by MEXT, Japan . This research was financially supported by JST-CREST (project code JPMJCR1423 ). S.Ø.S and T.N. acknowledge support from the Research Council of Norway (RCN) project 216039 ”NaProCs”.
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2018/2
Y1 - 2018/2
N2 - Surface protonic transport on cerium oxide (CeO2) was investigated using electrochemical impedance spectroscopy (EIS). CeO2 pellets showing low relative density: approximately 60%, was prepared for the purpose. The structure and morphology of the prepared CeO2 pellets were confirmed from XRD and SEM measurements. Results show that the pellets had a pure cubic phase, with open pores on which water can be adsorbed. Electrochemical impedance spectroscopy measurements were taken to evaluate the surface protonic transport on CeO2 as a function of temperature and as a function of partial pressure of water (PH2O) at 400 °C. Investigations of the temperature dependence of the conductivity revealed that only the conductivities of surface grain bulk (σintra) and surface grain boundary (σinter) increased with decreasing temperatures under wet conditions (PH2O = 0.026 atm). The PH2O dependence of surface conductivities (σintra and σinter) revealed that σintra increases strongly with PH2O at 400 °C. These findings provide evidence that water adsorbates play an important role in surface protonic transport on CeO2 at low temperatures. Surface protonic transport at low temperatures can contribute to the expansion of applications for electrical and catalytic processes.
AB - Surface protonic transport on cerium oxide (CeO2) was investigated using electrochemical impedance spectroscopy (EIS). CeO2 pellets showing low relative density: approximately 60%, was prepared for the purpose. The structure and morphology of the prepared CeO2 pellets were confirmed from XRD and SEM measurements. Results show that the pellets had a pure cubic phase, with open pores on which water can be adsorbed. Electrochemical impedance spectroscopy measurements were taken to evaluate the surface protonic transport on CeO2 as a function of temperature and as a function of partial pressure of water (PH2O) at 400 °C. Investigations of the temperature dependence of the conductivity revealed that only the conductivities of surface grain bulk (σintra) and surface grain boundary (σinter) increased with decreasing temperatures under wet conditions (PH2O = 0.026 atm). The PH2O dependence of surface conductivities (σintra and σinter) revealed that σintra increases strongly with PH2O at 400 °C. These findings provide evidence that water adsorbates play an important role in surface protonic transport on CeO2 at low temperatures. Surface protonic transport at low temperatures can contribute to the expansion of applications for electrical and catalytic processes.
KW - A. Cerium oxide
KW - B. Low relative density
KW - D. Surface protonics
KW - E. AC impedance measurement
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U2 - 10.1016/j.ssc.2017.11.010
DO - 10.1016/j.ssc.2017.11.010
M3 - Article
AN - SCOPUS:85035071784
SN - 0038-1098
VL - 270
SP - 45
EP - 49
JO - Solid State Communications
JF - Solid State Communications
ER -