Abstract: A catalyst composition for use in electrochemical reactor devices comprising platinum, ruthenium, and osmium and having a single phase crystal structure comprising a face centered cubic unit cell. In accordance with a particularly preferred embodiment, in atomic percentages, platinum comprises about 65% of the catalyst composition, ruthenium comprises about 25% of the catalyst composition, and osmium comprises about 10% of the catalyst composition.

Abstract: A hybrid electrolyte system for fuel cells and other electrochemical reactors comprising an acid electrolyte, a base electrolyte, and a proton permeable dense phase separating the acid electrolyte from the base electrolyte.

Abstract: A glass or glass-ceramic sealant for a SOFC having a coefficient of thermal expansion in the range of from about 8 to about 13.times.10.sup.-6 /.degree.C. and a viscosity of at least 10.sup.3 Pa-s at cell operating temperature. The sealant has a composition of SrO present in the range of from about 5 to about 60 mole percent, La.sub.2 O.sub.3 present in the range of from 0 to about 45 mole percent, Al.sub.2 O.sub.3 present in the range from 0 to about 15 mole percent, B.sub.2 O.sub.3 present in the range of from about 15 mole percent to about 80 mole percent, and SiO.sub.2 present in the range of from 0 to about 40 mole percent, wherein the material is a viscous fluid at cell operating temperatures of from about 600.degree. C. to about 1000.degree. C. The sealant may also be compounds of CaO present in the range of from 0 to about 35 mole percent, Al.sub.2 O.sub.3 present in the range from 0 to about 15 mole percent, B.sub.2 O.sub.