Abstract: An improved highly oxygen permeable substrate is provided comprising Sr--Fe--Co-oxide and a metal combined with said material. Also provided is a method for producing an improved membrane to facilitate oxidation of compounds comprising combining metal or metal alloys with Sr--Fe--Co-oxide to create a mixture, and sintering the mixture so as to allow the metal to melt within the mixture. The membrane is also utilized in a method for converting methane to syngas whereby a fluid containing oxygen is contacted to a first surface of the membrane for a sufficient period of time so as to cause some of the oxygen to be transported to a second surface of the membrane; and contacting methane to the second surface for a sufficient period of time to cause oxidation of the methane.

Abstract: For a combination of a membrane of SrFeCo.sub.0.5 O.sub.x and an Inconel alloy, a high-temperature seal is formed between the membrane and the alloy. The seal is interposed between the alloy and the membrane, and is a fritted compound of Sr oxide and boric oxide and a fritted compound of Sr, Fe and Co oxides. The fritted compound of SrFeCo.sub.0.50 O.sub.x is present in the range of from about 30 to 70 percent by weight of the total sealant material and the fritted compound of Sr oxide and boric oxide has a mole ratio of 2 moles of the Sr oxide for each mole of boric oxide. A method of sealing a ceramic to an Inconel metal alloy is also disclosed.