TY - JOUR
T1 - The enhanced electrochemical response of Sr(Ti0.3Fe0.7Ru0.07)O3-: δ anodes due to exsolved Ru-Fe nanoparticles
AU - Glaser, R.
AU - Zhu, T.
AU - Troiani, H.
AU - Caneiro, A.
AU - Mogni, L.
AU - Barnett, S.
N1 - Funding Information:
The authors at Northwestern University gratefully acknowledge nancial support by the US Department of Energy (Grant # DESC0016965) and those at Centro Atomico acknowledge AGNP-CyT PICT 2016-2965, CONICET PIP0565 and Universidad Nacional de Cuyo. Tenglong Zhu gratefully acknowledges the scholarship from the State Scholarship Fund of the China Scholarship Council (201406430041). The authors acknowledge the assistance of the Electron Probe Instrumentation Center (EPIC) at the NUANCE Center-Northwestern University, which has received support from the So and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. The authors also acknowledge YPF Tecnología (Y-TEC) for the use of the TALOS microscope.
Funding Information:
The authors at Northwestern University gratefully acknowledge financial support by the US Department of Energy (Grant # DE-SC0016965) and those at Centro Atomico acknowledge AGNPCyT PICT 2016-2965, CONICET PIP0565 and Universidad Nacional de Cuyo. Tenglong Zhu gratefully acknowledges the scholarship from the State Scholarship Fund of the China Scholarship Council (201406430041). The authors acknowledge the assistance of the Electron Probe Instrumentation Center (EPIC) at the NUANCE Center-Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF NNCI-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. The authors also acknowledge YPF Tecnología (Y-TEC) for the use of the TALOS microscope.
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
PY - 2018
Y1 - 2018
N2 - A mixed conducting oxide with a nominal composition Sr(Ti0.3Fe0.7Ru0.07)O3-δ (STFRu) is studied, in comparison with SrTi0.3Fe0.7O3-δ (STF) oxide, as an anode for solid oxide fuel cells. Exposing STFRu to reducing fuel conditions at 800 °C for 4 h results in the exsolution of essentially all of the Ru and a small fraction of the Fe from the oxide, and the formation of Ru1-xFex nanoparticles on the oxide surfaces. Most of the nanoparticles have the hexagonal structure expected for Ru-rich alloys, and thermogravimetric analysis suggests the composition x ∼ 0.2. A small fraction of bcc-structure, presumably Fe-rich, nanoparticles are also detected. Comparison of cells with STFRu and STF anodes shows that the presence of Ru induces a reduced polarization resistance and increases the maximum power density under most cell operating conditions, particularly at lower temperatures and hydrogen partial pressures. For example, at 700 °C and 30% H2 fuel, the maximum power density is 0.1 W cm-2 for STF compared to 0.3 W cm-2 for STFRu. There is also a significant change in the shape of the current-voltage curves and the pH2-dependence of the anode polarization resistances RP,A ∝ (pH2)-m, from m ∼ 0.5-1.0 for STF to m ∼ 0.11-0.29 for STFRu; these suggest that Ru1-xFex nanoparticles improve anode performance by promoting hydrogen adsorption.
AB - A mixed conducting oxide with a nominal composition Sr(Ti0.3Fe0.7Ru0.07)O3-δ (STFRu) is studied, in comparison with SrTi0.3Fe0.7O3-δ (STF) oxide, as an anode for solid oxide fuel cells. Exposing STFRu to reducing fuel conditions at 800 °C for 4 h results in the exsolution of essentially all of the Ru and a small fraction of the Fe from the oxide, and the formation of Ru1-xFex nanoparticles on the oxide surfaces. Most of the nanoparticles have the hexagonal structure expected for Ru-rich alloys, and thermogravimetric analysis suggests the composition x ∼ 0.2. A small fraction of bcc-structure, presumably Fe-rich, nanoparticles are also detected. Comparison of cells with STFRu and STF anodes shows that the presence of Ru induces a reduced polarization resistance and increases the maximum power density under most cell operating conditions, particularly at lower temperatures and hydrogen partial pressures. For example, at 700 °C and 30% H2 fuel, the maximum power density is 0.1 W cm-2 for STF compared to 0.3 W cm-2 for STFRu. There is also a significant change in the shape of the current-voltage curves and the pH2-dependence of the anode polarization resistances RP,A ∝ (pH2)-m, from m ∼ 0.5-1.0 for STF to m ∼ 0.11-0.29 for STFRu; these suggest that Ru1-xFex nanoparticles improve anode performance by promoting hydrogen adsorption.
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U2 - 10.1039/c7ta10762e
DO - 10.1039/c7ta10762e
M3 - Article
AN - SCOPUS:85044210350
SN - 2050-7488
VL - 6
SP - 5193
EP - 5201
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 12
ER -
