Praxair Technology, Inc.

Pawel J Plonczak

Jonathan Andrew Lane

Zigui Lu

Sean Michael Kelly

Gervase Maxwell Christie

Joseph M Corpus

Jiefeng Lin

Uttam R Doraswami

Yunxiang Lu

A method is described of producing a catalyst-containing composite oxygen ion membrane and a catalyst-containing composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (LnA)CrBOand a doped zirconia. Adding certain catalyst metals into the fuel oxidation layer not only enhances the initial oxygen flux, but also reduces the degradation rate of the oxygen flux over long-term operation. One of the possible reasons for the improved flux and stability is that the addition of the catalyst metal reduces the chemical reaction between the (LnA)CrBOand the zirconia phases during membrane fabrication and operation, as indicated by the X-ray diffraction results.

Catalyst-containing oxygen transport membrane

A dual function composite oxygen transport membrane having a layered structure of mixed conducting oxygen transport materials on a first side of a porous substrate and a reforming catalyst layer on an opposing second side of the porous substrate. The layered structure of the mixed conducting oxygen transport materials contains an intermediate porous layer of mixed conducting oxygen transport materials formed on the porous substrate with a dense impervious layer of mixed conducting oxygen transport materials over the intermediate porous layer, and an optional surface exchange layer of mixed conducting oxygen transport materials over the dense impervious layer. The layered structure and the reforming catalyst layer are formed in separate steps.

Dual function composite oxygen transport membrane

A composite oxygen ion transport membrane having a dense layer, a porous support layer, an optional intermediate porous layer located between the porous support layer and the dense layer and an optional surface exchange layer, overlying the dense layer. The dense layer has electronic and ionic phases. The ionic phase is composed of scandia doped, yttrium or cerium stabilized zirconia. The electronic phase is composed of a metallic oxide containing lanthanum, strontium, chromium, iron and cobalt. The porous support layer is composed of zirconia partially stabilized with yttrium, scandium, aluminum or cerium or mixtures thereof. The intermediate porous layer, if used, contains the same ionic and electronic phases as the dense layer. The surface exchange layer is formed of an electronic phase of a metallic oxide of lanthanum and strontium that also contains chromium, iron and cobalt and an ionic phase of scandia doped zirconia stabilized with yttrium or cerium.

Composite oxygen ion transport membrane

A method is described of producing a composite oxygen ion membrane and a composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (LnA)CrBOand a doped zirconia. Preferred materials are (LaSr)CrFeOfor the porous fuel oxidation layer, (LaSr)CrFeOfor the dense separation layer, and (LaSr)CrFeOfor the porous surface exchange layer. Firing the said fuel activation and separation layers in nitrogen atmosphere unexpectedly allows the separation layer to sinter into a fully densified mass.

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Amherst, NY, United States of America

Pawel J Plonczak