Catalytic Activity of Ceria-Based Complex Metal Oxides in Alkaline and Acidic Environments

2013 ◽  
Vol 1542 ◽  
Author(s):  
Matthew C Schrandt ◽  
Praveen Kolla ◽  
A. Smirnova
Keyword(s):  
Catalytic Activity ◽  
Solid Oxide Fuel Cells ◽  
Low Temperatures ◽  
Catalytic Reduction ◽  
Electronic Conductivity ◽  
Solid Oxide ◽  
Pt Catalysts ◽  
Complex Metal Oxides ◽  
Acidic Environments ◽  
Limited Supply

ABSTRACTPt catalysts are the leading catalysts for use in ORR. However, Pt is an expensive catalyst and with limited supply can not be considered a sustainable material for feasible application that is scalable in the economy. This calls for new solutions for catalyst materials that either mitigate the amount of Pt used in catalysts by developing hybrid catalysts, or to replace Pt altogether with a material with similar or better catalytic activity. Perovskite LSCF and Fluorite GDC materials with proven catalytic activity in solid oxide fuel cells are herein explored for their catalytic reduction of oxygen for use at low temperatures. Since the materials lack electronic conductivity at low temperatures, we have improved their conductivity with graphene. The resulting materials are compared to Pt in their ORR catalytic capabilities and electronic conductivity.

Electronic Behavior of Ba0.5Sr0.5Co0.8Fe0.2O3-d and SrCo0.9Nb0.1O3-d

2011 ◽  
Vol 1331 ◽  
Author(s):  
Robert E. Usiskin ◽  
Richard Y. Wang ◽  
Sossina M. Haile
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electronic Conductivity ◽  
Defect Chemistry ◽  
Solid Oxide ◽  
High Catalytic Activity ◽  
Membrane Material ◽  
Comparable Performance ◽  
Oxygen Reduction Catalyst ◽  
Hole Migration ◽  
Electronic Behavior

ABSTRACTThe perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF 5582) has attracted great interest as an oxygen reduction catalyst for solid oxide fuel cells and as an oxygen permeation membrane material. Mixed ionic and electronic conductivity is essential to the high catalytic activity it exhibits, however its electronic behavior and overall defect chemistry are not well understood. The related material SrCo0.9Nb0.1O3-d (SCN 091) is another promising composition that may have comparable performance, but with defect chemistry that is simpler to study. From a combination of thermogravimetric, impedance, and diffraction measurements we find SCN 091 to exhibit somewhat smaller oxygen nonstoichiometry, five times higher electronic conductivity, lower enthalpy of hole migration, and greater structural stability than BSCF 5582. We also observe that the enthalpy of hole migration in such materials tends to increase as oxygen content decreases; the origins of this behavior are unclear.

Enhancing the Catalytic Activity of Y0.08Sr0.92TiO3−δ Anodes through in Situ Cu Exsolution for Direct Carbon Solid Oxide Fuel Cells

2020 ◽  
Vol 59 (29) ◽  
pp. 13105-13112 ◽  
Author(s):  
Jinshuo Qiao ◽  
Haitao Chen ◽  
Zhenhua Wang ◽  
Wang Sun ◽  
Haijun Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Oxide Fuel

scholarly journals Development of novel air electrode materials for the SOFC and SOEC technologies

2019 ◽  
Vol 108 ◽  
pp. 01019 ◽  
Author(s):  
Anna Niemczyk ◽  
Konrad Świerczek
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrode Materials ◽  
Operating Temperature ◽  
Electronic Conductivity ◽  
Reduction Reaction ◽  
Significant Decline ◽  
Solid Oxide ◽  
Air Electrode ◽  
Good Catalytic Activity ◽  
New Compounds

One of major goals in the development of solid oxide fuel cells and its reversible mode, solid oxide electrolyzer cells, is related to a decrease of the operating temperature, down to the intermediate range (600-800 °C) or even lower temperatures. However, this reduction causes an increase of the polarization resistance, especially for the air electrode, which results in a significant decline of the efficiency of the device. Therefore, it is essential to obtain new, thermally and chemically stable materials with the high ionic-electronic conductivity and good catalytic activity for the oxygen reduction reaction working in the decreased temperature range. At the same time, environmental and economic aspects have to be considered in the development of the new compounds. Promising cobalt-free electrode materials can be Cu-based oxides with the perovskite and perovskite-related structures.

scholarly journals Metal Exsolution to Enhance the Catalytic Activity of Electrodes in Solid Oxide Fuel Cells

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2445
Author(s):  
Tianyu Cao ◽  
Ohhun Kwon ◽  
Raymond J. Gorte ◽  
John M. Vohs
Keyword(s):  
Catalytic Activity ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Catalytic Properties ◽  
Solid Oxide ◽  
Metal Particles ◽  
Metal Catalyst ◽  
Oxide Fuel ◽  
Novel Technology ◽  
Metal Incorporation

Exsolution is a novel technology for attaching metal catalyst particles onto ceramic anodes in the solid oxide fuel cells (SOFCs). The exsolved metal particles in the anode exhibit unique properties for reaction and have demonstrated remarkable stabilities under conditions that normally lead to coking. Despite extensive investigations, the underlying principles behind exsolution are still under investigation. In this review, the present status of exsolution materials for SOFC applications is reported, including a description of the fundamental concepts behind metal incorporation in oxide lattices, a listing of proposed mechanisms and thermodynamics of the exsolution process and a discussion on the catalytic properties of the resulting materials. Prospects and opportunities to use materials produced by exsolution for SOFC are discussed.

scholarly journals A highly active Ni/Ce0.8Sm0.2O1.9 anode catalyst with a three-dimensionally ordered macroporous structure for solid oxide fuel cells

2020 ◽  
Vol 8 (16) ◽  
pp. 7792-7800 ◽  
Author(s):  
Tian Gan ◽  
Xinqiang Fan ◽  
Ye Liu ◽  
Chengyu Wang ◽  
Haoran Mei ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Solid Oxide Fuel Cells ◽  
Anode Material ◽  
Solid Oxide ◽  
High Catalytic Activity ◽  
Oxide Fuel ◽  
Macroporous Structure ◽  
Anode Catalyst ◽  
Highly Active ◽  
Ordered Macroporous

Ni/3DOM Ce0.8Sm0.2O1.9 shows a high catalytic activity as the anode material of CH3OH fueled SOFCs.

Effects of trivalent dopants on phase stability and catalytic activity of YBaCo4O7-based cathodes in solid oxide fuel cells

2018 ◽  
Vol 6 (34) ◽  
pp. 16412-16420 ◽  
Author(s):  
Ke-Yu Lai ◽  
Arumugam Manthiram
Keyword(s):  
Catalytic Activity ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Phase Stability ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Oxide Fuel ◽  
Co Doping ◽  
Doping Effects ◽  
Trivalent Cations

In order to understand the doping and co-doping effects of trivalent cations (Al3+, Ga3+, and Fe3+) in the swedenborgite oxide YBaCo4O7 as a cathode in intermediate-temperature SOFCs, four series of YBaCo4O7-based materials, including YBaCo4−xAlxO7+δ, YBaCo4−x−yGaxAlyO7+δ, YBaCo3.2Ga0.8−xFexO7+δ, and YBaCo3.5−xAl0.5FexO7+δ, have been synthesized and investigated.

Order-Disorder Transitions in Gadolinium Zirconate: A Potential Electrolyte Material in Solid Oxide Fuel Cells

1995 ◽  
Vol 393 ◽  
Author(s):  
Scott Meilicke ◽  
Sossina Haile
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Transition Temperature ◽  
Ionic Conductivity ◽  
Solid Oxide Fuel Cells ◽  
Low Temperatures ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Gadolinium Zirconate ◽  
X Ray

ABSTRACTRare-earth, yttrium, and calcium doped zirconates are the materials of choice for electrolytes in solid oxide fuel cells. The dopant in these materials serves not only to stabilized the cubic phase of zirconia, but also to introduce anion defects that presumably increase the ionic conductivity. In order to understand the relationships between anion defect distribution, thermal history and ionic conductivity, the structural properties of gadolinium zirconate, Gd2Zr207, have been examined via high-temperature x-ray powder diffraction. Gadolinium zirconate is an ideal material for such a structure-property-processing study: it shows ordering of defects at low temperatures, taking on a pyrochlore structure, and disordering at elevated temperature, taking on a defect fluorite structure. Diffraction experiments, performed as functions of time and temperature, confirmed the transition temperature to lie between 1500 and 1550 °C. They also revealed that the transformation takes place most rapidly just below the transition temperature, indicating that the ordering process is kinetically constrained at low temperatures. Moreover, x-ray data collected at room temperature from quenched samples were found to be as useful, if not more so, than those collected in situ at high temperature. The latter are affected by thermal scattering, severely compromising data quality.

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