Solid oxide fuel cell anodes

Reactions (3.9) to (3.11) proceed rapidly to equilibrium in most anodic solid oxide fuel cell (SOFC) environments and thus H2 (Eq. 3.8) rather than CH4 is oxidized electrochemically resulting in low polarization losses. Upon doubling the stoichiometric coefficients of equation (3.8), summing equations (3.8) to (3.11) and dividing the resulting coefficients by two one obtains ... 

Guzman, F., Singh, R., Chuang, S.S.C. (2011) Direct use of sulfur-containing coke on a Ni—Yttria-stabilized Zirconia anode solid oxide fuel cell. Energy Fuels, 25 (5), 2179-2186. 

Table 3.1 lists some of the anodic reactions which have been studied so far in small cogenerative solid oxide fuel cells. A more detailed recent review has been written by Stoukides46 One simple and interesting rule which has emerged from these studies is that the selection of the anodic electrocatalyst for a selective electrocatalytic oxidation can be based on the heterogeneous catalytic literature for the corresponding selective catalytic oxidation. Thus the selectivity of Pt and Pt-Rh alloy electrocatalysts for the anodic NH3 oxidation to NO turns out to be comparable (>95%) with the... 

This reaction is of great technological interest in the area of solid oxide fuel cells (SOFC) since it is catalyzed by the Ni surface of the Ni-stabilized Zr02 cermet used as the anode material in power-producing SOFC units.60,61 The ability of SOFC units to reform methane "internally", i.e. in the anode compartment, permits the direct use of methane or natural gas as the fuel, without a separate external reformer, and thus constitutes a significant advantage of SOFC in relation to low temperature fuel cells. 

Solid oxide fuel cell, SOFC anodes, 97 catalysis in, 98,410 cathodes, 96... 

This presentation reports some studies on the materials and catalysis for solid oxide fuel cell (SOFC) in the author s laboratory and tries to offer some thoughts on related problems. The basic materials of SOFC are cathode, electrolyte, and anode materials, which are composed to form the membrane-electrode assembly, which then forms the unit cell for test. The cathode material is most important in the sense that most polarization is within the cathode layer. The electrolyte membrane should be as thin as possible and also posses as high an oxygen-ion conductivity as possible. The anode material should be able to deal with the carbon deposition problem especially when methane is used as the fuel. 

Performance of an Anode-supported Solid Oxide Fuel Cell in a Mixed-gas Configuration... 

There has been considerable interest in Ce02 as a component of solid oxide fuel cells, especially as an anode material, and also for use in oxygen separation membranes. The material shows a wide nonstoichiometry range, with oxygen vacancies as the... 

FIGURE 2.8 (a) Porosity versus sintering temperatures for Ni-YSZ cermets sintered for different times (2, 4, and 6 h) (b) Anode conductivity versus porosity for the Ni-YSZ cermets with Ni to YSZ volume ratio of 40 60. (From Pratihar, S.K. et al., Proceedings of the Sixth International Symposium on Solid Oxide Fuel Cells, 99(19) 513—521. Reproduced by permission of ECS-The Electrochemical Society.)... 

However, despite those positive reports, the authors would not recommend precalcination of the starting NiO-YSZ powder mixture as a necessary step in the processing of solid oxide fuel cells for the following reasons. First, the mechanism for the enhanced electrochemical performance for anodes when the NiO-YSZ precalcinated together has not been explained clearly. The phenomenon is actually counterintuitive because it has been shown that coarsening of NiO or YSZ alone leads to lower anode... 

Summary of Previous Studies on Potential Sulfur-Tolerant Anode Materials for Solid Oxide Fuel Cells... 

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