201 results about "Double perovskites" patented technology

The invention discloses a double-perovskite type intermediate temperature solid oxide fuel cell anode material and a preparation method and belongs to the technical field of solid oxide fuel cells. The molecular formula of the anode material is A2Co<1-x>MxFeO<5+delta>, wherein A is Ca, Sr or Ba element, M is Mo, Nb, Ti, Ni, Cu or Al element, and x is greater than 0 and smaller than 1. The preparation method comprises the following steps: required solonetz nitrate and the like as well as a complexing agent are uniformly mixed in an aqueous solution to obtain gel, the gel is oven-dried, the oven-dried gel is calcined at 500-700 DEG C and 800-950 DEG C respectively, and the calcined powder is sintered at 1100-1300 DEG C for 10-20 hours to obtain the corresponding one-phase double-perovskite type anode material. The anode material has the characteristics of low cost, excellent conductivity, low coefficient of thermal expansion and chemistry compatibility with electrolyte material and is the intermediate temperature solid oxide fuel cell anode material having excellent application prospect.

The utility model discloses a rare earth catalyst used in preparation of syngas through biomass and coal in supercritical water in co-gasification mode, in particular to a rare earth catalyst used for catalyzing gasified biomass to coal to prepare the syngas in the supercritical water. The rare earth catalyst selected in the method is rare earth double-perovskite type composite oxide containing lanthanum, cobalt and manganese. The catalyst is used for catalyzing the supercritical water co-gasification reaction of the biomass and the coal to obtain the syngas with the content reaching 63.4%, so that content of carbon monoxide in gas products increases, and content of carbon dioxide is remarkably reduced.

The invention discloses a preparation method of a double-perovskite ferroelectric (FET)-antiferromagnetic (AFM) compound molecule with an oxygen bridge. In the invention, a method for compounding an FET molecule with an AFM molecule with different physical properties is described. A chemically-synthesized AFF (Antiferromagnetism-ferroelectrics) material can form an ABO3 double-perovskite compound structure with an oxygen bridge Bafm-O-Bfet. A method for compounding BaTiO3 serving as an FET typical material with NdBaMnO3 serving as an AFM typical material is taken as an example in the invention.

The present invention relates to a strontium magnesium molybdenum oxide material having perovskite structure and the method for preparing the same. Citric acid is adopted as the chelating agent. By using sol-gel pyrolysis and replacing a portion of strontium in Sr₂MgMoO_6-δ by cerium and a portion of magnesium by copper, a material with a chemical formula of Sr_2-xCe_xMg_1-yCu_yMoO_6-δ is produced, where 0≦x<2, 0<y<1, and 0<δ<6. Thereby, the electrical conductivity of the material is improved. The perovskite-type cerium- and copper-replaced strontium magnesium molybdenum oxide significantly increases the electrical conductivity of the material and can be applied as the anode material for solid oxide fuel cell (SOFC).

The invention discloses a high-conductivity double-perovskite-type anode material and a preparation method thereof and belongs to the field of solid oxide fuel cells. The high-conductivity double-perovskite-type anode material is characterized in that a B site of a double-perovskite-type (A2BB'O6) solid oxide fuel cell anode material Sr2MgMoO6 is doped with Y so that the high-conductivity double-perovskite-type anode material which is a mixed conductor having a double-perovskite structure is obtained. The preparation method provided by the invention comprises the following steps of pressing B site-doped Sr2Mg1-xYxMoO6 powder (x is in a range of 0.1 to 0.2) into a sample strip under certain pressure, carrying out sintering at a high temperature in an air atmosphere, carrying out reduction under reduction conditions, and carrying out conductivity measuring, wherein compared with a conductivity measured before doping, a conductivity measured after doping is improved 5.8 times (x=0.2). Through the preparation method provided by the invention, the high-conductivity double-perovskite-type anode material which is a porous film-type anode material Sr2Mg1-xYxMoO6 (x is in a range of 0.1 to 0.2) is obtained, and has good combinability and good chemical compatibility with electrolytes of GDC and LSGM, and carbon distribution-resistant and sulfur poisoning-resistant capabilities higher than carbon distribution-resistant and sulfur poisoning-resistant capabilites of the traditional anode material.

The invention relates to an A-site doping type double-perovskite catalyst as well as a preparation method and an application thereof, and belongs to the technical field of catalysts. The general chemical formula of the A-site doping type double-perovskite catalyst is A(2-x)A'xBB'O6, wherein A is rare earth metal La, Ce, Nd or Gd; A' is alkaline-earth metal Mg, Ca, Sr or Ba; B is transition metal Co, Fe, Ni, Cu, Mn or Mo; B' is transition metal Co, Fe, Ni, Cu, Mn or Mo, and B is different from B'. The doping type double-perovskite nanocatalyst A(2-x)A'xBB'O6 with regular morphology is preparedin a NaNO3 and KNO3 molten salt system with a molten salt process. Nitric oxide can be catalytically oxidized into nitrogen dioxide by the A-site doping type double-perovskite catalyst at lower temperature in wider temperature range.

The invention relates to a V-doped YBCO (Yttrium Barium Copper Oxide) superconducting thin film and a preparation method thereof, and belongs to the technical field of preparation of YBCO coating superconducting thin films. The preparation method of a double perovskite structure nanoparticle BYVO-doped YBCO superconducting thin film comprises the following steps: 1) first, preparing a precursor liquor, and mixing yttrium acetate, barium acetate and copper acetate at a molar ratio of 1:2:3 to prepare a YBCO precursor liquor; 2) uniformly stirring and then vanadium acetylacetonate, wherein the molar concentration of three metal total ions to prepare the V-doped YBCO precursor liquor; 3) coating a gel thin film; 4) sintering at low temperature; and 5) sintering at high temperature to form the nano BYVO containing YBCO superconducting thin film. The method provided by the invention is simple and accessible, and the proportion of adulterants can be arbitrarily controlled. The thin film prepared has the advantages of higher critical transformation temperature and critical current density and a good biaxial texture.

The invention relates to a method for hydrogen production by reforming of hydrogen sulfide and methane. According to the invention, hydrogen sulfide and methane are subjected to contact reaction withthe catalyst La2NiFeO6. The double-perovskite structure composite metal oxide is applied as a catalyst in the reaction of hydrogen production by reforming of hydrogen sulfide and methane. The catalysthas better high temperature thermal stability and higher activity than single oxide (like Al2O3). As the reaction is carried out at a high temperature of 800DEG C-1100DEG C, the composite oxide withthe double-perovskite structure is more suitable the reaction. In addition, the catalyst has high activity in catalyzing the reforming of hydrogen sulfide and methane for hydrogen production.

The invention relates to a B-site doped double-perovskite catalyst as well as a preparation method and application thereof and belongs to the technical field of catalysts. The B-site doped double-perovskite catalyst has a chemical formula A2B1-xMxB'O6, in the formula A is a rare-earth metal element La, Ce, Nd or Gd; B is Co, Fe, Ni, Cu, Mn, Mo, Al or Ga; B' is Co, Fe, Ni, Cu, Mn, Mo, Al or Ga; M is a transition metal Co, Fe, Ni, Cu, Mn or mo; B is not equal to B'. By using a melting salt method, the B-site doped double-perovskite catalyst A2B1-xMxB'O6 with a nano regular morphology is preparedin the melting salt system of NaNO3 and KNO3. The B-site doped double-perovskite catalyst is capable of efficiently catalyzing and oxidizing nitric oxide into nitric dioxide at a relatively low temperature within a relatively wide temperature range, and in addition, the method provided by the invention is simple in process, easy to operate, low in cost and easy in industrial production.

The invention discloses a double-perovskite-type anode material and a preparation method thereof, and belongs to the technical field of solid oxide fuel batteries. The site Mg and the site Mo of the anode material LaxSr(2-x)MgMoO6 of a double-perovskite (A2BB'O6) solid oxide fuel battery are simultaneously doped with Fe, so that a high-performance and high-stability double-perovskite structured blended conductor material is formed. The molecular formula of the double-perovskite-type anode material is LaxSr(2-x)Mg(1-y)Fe2yMo(1-y)O(6-delta), wherein x is greater than 0 and smaller than 1, y is greater than 0 and smaller than 1, and delta is greater than or equal to 0 and smaller than or equal to 1. The invention also discloses a compact-type anode material and a porous film anode material. The double-perovskite-type anode material has the technical effects that according to a charge compensation principle, the site Mg and the site Mo are simultaneously doped with Fe to achieve charge self-consistency of a material system, so that the redox stability of the material is effectively improved; cheap Fe is selected as a doping element, so that the cost of the material can be lowered; meanwhile, Fe is relatively high in valence change capacity, so that an effective conductive network can be formed on the site B, and the catalysis activity and the conductivity of the material are improved favorably.