The Dow Chemical Company

Sunil D Wijeyesekera

Sten A Wallin

Arthur Richard Prunier, Jr

Robert H Heistand, Ii

Stanley F Spangenberg

A high performance electrocatalyst is based on transition metal perovskites of praseodymium, samarium, terbium or neodymium which react with YSZ to form a product which is itself active as the cathode in a fuel cell. While PrCoO reacts with YSZ, the reaction product(s) do not result in severe degradation of cell performance. A fuel cell made with a cathode composed of only the reaction product of YSZ and PrCoO has good performance, indicating that this phase is itself not only a good conductor, but also a good catalyst for oxygen activation.

Cathode composition for solid oxide fuel cell

A high performance electrocatalyst is based on transition metal perovskites of praseodymium, samarium, terbium or neodymium which react with YSZ to form a product which is itself active as the cathode in a fuel cell. While PrCoO,reacts with YSZ, the reaction product(s) do not result in severe degradation of cell performance. A fuel cell made with a cathode composed of only the reaction product of YSZ and PrCoO,has good performance, indicating that this phase is itself not only a good conductor, but also a good catalyst for oxygen activation.

A high performance electrocatalyst is based on transition metal perovskites of praseodymium, samarium, terbium or neodymium which react with YSZ to form a product which is itself active as the cathode in a fuel cell. While PrCoO.sub.3 reacts with YSZ, the reaction product(s) do not result in severe degradation of cell performance. A fuel cell made with a cathode composed of only the reaction product of YSZ and PrCoO.sub.3 has good performance, indicating that this phase is itself not only a good conductor, but also a good catalyst for oxygen activation.

A planar solid oxide fuel cell stack has a number of fuel cells (anode/electrolyte/cathode) connected in series by a gas tight, electrically conductive interconnection in which at least one electrode is a porous composite of a contiguous network of an ionically conductive material or phase, a contiguous network of an electrically conductive material or phase, and a highly efficient electrocatalyst material or phase which is dispersed within the pores of the electrode so that the electrocatalyst material or phase particles are in contact with both the ionically conductive material or phase and the electrically conductive material or phase. The electrocatalyst particles are introduced into the electrode of the assembled stack by infiltrating the pores of the electrode with a precursor solution through the fuel gas or oxidant gas manifolding connections, respectively. The stack assembly is then heat treated to form small, highly active particles of the dispersed electrocatalyst material or phase within the electrode.

Solide oxide fuel cell stack with composite electrodes and method for

This invention provides a process for producing a ceramic body by heating a ceramic material, such as particulate zirconium oxide, to a temperature greater than about 30 percent of the material's melting temperature, but less than said melting temperature, and thereafter applying sufficient isostatic pressure to consolidate the ceramic material into a body having a density of at least 85 percent of the theoretical density of the material. This invention also provides a process for producing superconducting ceramic articles such as those represented by the general formula YBa.sub.2 Cu.sub.3 O.sub.7-x where 0&lt;x&lt;0.6. Starting materials for such articles include sources of yttria, cupric oxide and barium monoxide. The general process parameters for the ceramic body process are modified to accomodate the starting materials. The ceramic body process is further modified by an optional precursor step wherein the starting materials are placed in a container and by certain finishing steps including annealing and cooling in the presence of oxygen. This invention also concerns the ceramic body and the superconducting ceramic article prepared by the foregoing processes.

Method for producing ceramic bodies

Subject a heated, non-molten, intimate admixture of a base metal and a superconducting oxide material to pressure sufficient to form a densified article. The densified article is either superconducting as formed or capable of being rendered superconducting by annealing in the presence of oxygen. Depending upon the choice of materials the densified article is stable at temperatures up to 1000.degree. C.

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Midland, MI, United States of America

Sunil D Wijeyesekera