Hydrogen separation membrane on a porous substrate
AssigneeUchicago Argonne, LLC
InventorsSun-Ju Song, Tae H. Lee, Ling Chen, Stephen E. Dorris, Uthamalingam Balachandran
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Abstract
A hydrogen permeable membrane is disclosed. The membrane is prepared by forming a mixture of metal oxide powder and ceramic oxide powder and a pore former into an article. The article is dried at elevated temperatures and then sintered in a reducing atmosphere to provide a dense hydrogen permeable portion near the surface of the sintered mixture. The dense hydrogen permeable portion has a higher initial concentration of metal than the remainder of the sintered mixture and is present in the range of from about 20 to about 80 percent by volume of the dense hydrogen permeable portion.
Claims18
A hydrogen permeable membrane on a porous support prepared by:
- (a) forming a mixture of metal oxide powder and ceramic oxide powder and optionally a pore former;
- (b) pressing the mixture to form an article;
- (c) pre-sintering the article at an elevated temperature in air to remove at least some of the pore former if present and to impart mechanical integrity and porosity to the article;
- and
- (d) thereafter sintering the article in a reducing atmosphere to reduce metal oxide near the surface of the article to a metal and leave metal oxide in the core of the article, and thereby provide a dense hydrogen permeable portion near the surface of the sintered mixture and a porous core having a lower density relative to the dense surface layer;
- wherein the dense hydrogen permeable portion has a higher initial concentration of metal than the remainder of the sintered mixture, the metal oxide is selected from the group consisting of oxides of Ni, Pd, Pd alloys, and mixtures thereof, the ceramic oxide is selected from the group consisting of yttria stabilized zirconia, shrinkable alumina, Y doped cerates, Gd doped cerates, titanates, barium zirconates strontium zirconates, and mixtures thereof, and the dense hydrogen permeable portion has a metal concentration in the range of from about 20 to about 80 percent by volume.
A hydrogen permeable membrane on a porous support prepared by:
- (a) forming a mixture of metal oxide powder and ceramic oxide powder and a pore former;
- (b) pressing the mixture to form an article,
- (c) pre-sintering the article at about 700° C. in air to remove at least some of the pore former and to impart mechanical integrity and porosity to the article;
- and
- (d) thereafter sintering the article in a reducing atmosphere comprising about 200 ppm to about 4% hydrogen to reduce metal oxide near the surface of the article to a metal and leave metal oxide in the core of the article, and thereby provide a dense hydrogen permeable portion not greater than about 50 microns in thickness and at least about 96% of theoretical density near the surface of the sintered mixture and a porous core having a lower density relative to the dense surface layer;
- wherein the dense hydrogen permeable portion has a higher initial concentration of metal than the remainder of the sintered mixture, the metal oxide is selected from the group consisting of oxides of Ni, Pd, Pd alloys, and mixtures thereof, the ceramic oxide is selected from the group consisting of yttria stabilized zirconia, shrinkable alumina, Y doped cerates, Gd doped cerates, titanates, barium zirconates, strontium zirconates, and mixtures thereof, and the dense hydrogen permeable portion has a metal concentration in the range of from about 20 to about 80 percent by volume.
A hydrogen permeable membrane comprising a reduced sintered mixture of a metal oxide and a ceramic oxide, disposed on a porous substrate, the membrane comprising a dense hydrogen permeable metal-containing surface layer not greater than about 50 microns in thickness and at least about 96% of theoretical density and a porous metal-containing core having a lower density relative to the dense surface layer;
- wherein the dense hydrogen permeable metal-containing surface layer has a higher initial concentration of metal than the porous metal-containing core, the metal oxide is selected from the group consisting of oxides of Ni, Pd, Pd alloys, and mixtures thereof, the ceramic oxide is selected from the group consisting of yttria stabilized zirconia, shrinkable alumina, Y doped cerates, Gd doped cerates, titanates, barium zirconates, strontium zirconates, and mixtures thereof, and the dense hydrogen permeable metal-containing surface layer has a metal concentration in the range of from about 20 to about 80 percent by volume.
Dependencies are inferred from the claim text.