32results about How to "High oxygen storage" patented technology

The invention discloses a cubic phase cerium and zirconium based composite oxide with high specific surface area. Rare earth elements are doped in the cerium-zirconium composite oxide and are selected from two or three of Pr, Nd and La, wherein the molar ratio of Zr to Ce is (1.8-2.5):1; the molar ratio of Pr to Ce is (0-0.32):1; the molar ratio of Nd to Ce is (0-0.32):1; the molar ratio of La toCe is (0-0.16):1; and the cerium and zirconium based composite oxide exists in a form of cerium-zirconium solid solution. The invention also discloses a preparation method of the cerium and zirconiumbased composite oxide. The composite oxide is prepared through different precursor precipitating and drying methods; the method has the advantages of simple reaction process and low requirements on drying equipment; the obtained cerium and zirconium based composite oxide has high specific surface area, high thermal stability and high oxygen storage and discharge capacity; and after sintering is performed at the temperature of 1,000 DEG C for 12 hours, the specific surface area is more than 35m<2>/g, particularly more than 60m<2>/g.

The invention relates to a solid solution carrier catalyst and particularly relates to a multi-doped cerium-zirconium carrier catalyst. The chemical components of the catalyst in parts by weight are as follows: 30-40 parts of cerium oxide, 30-40 part of zirconia, 1-20 parts of other rare earth oxides and 1-5 parts of transition metal oxides, wherein the other rare earth oxides are lanthanum oxide, praseodymium oxide, neodymium oxide, yttrium oxide and samarium oxide and the transition metal oxides are vanadium oxide, chromium oxide, manganese oxide, ferric oxide, cobaltosic oxide and copper oxide. The invention further provides a preparation method of the catalyst. The preparation method comprises the following steps: mixing all the raw materials with a surfactant, adjusting the pH to 8-10 to obtain a gel-like deposition and calcining to obtain the product. According to the method, the doping defect caused during cerium-zirconium carrier doping is overcome; meanwhile, the thermal stability, aging specific area and oxygen storage amount of the carrier catalyst are improved; the invention also provides the preparation method which is simple in technique process and is favorable for large-scale industrial production.

The invention provides a nano ceria-zirconia solid solution and a method of preparing the solution. The chemical general formula of the nano ceria-zirconia solid solution is Ce1-XZrO2, wherein, X is 0.05 to 0.95. Compared with the prior art, the nano ceria-zirconia solid solution of the invention is characterized by small grain size, large specific surface area, high oxygen storage, high oxygen storage and release speed, and strong sintering resistant capability.

The invention provides a preparation method of a cerium-zirconium composite oxide with high oxygen storage capacity, wherein the cerium-zirconium composite oxide comprises cerium oxide, zirconium oxide and at least one oxide of element selected from rare earth metal elements other than cerium, and the method comprises the step of pretreatment of cerium, zirconium and salts of rare earth metals inthe process of preparing the cerium-zirconium composite oxide by a hydrothermal method, wherein the pretreatment is oxidation treatment. The preparation method can obtain the cerium-zirconium composite oxide with high oxygen storage capacity, and the cerium-zirconium composite oxide has a larger pore volume structure and specific surface area, has remarkable oxygen storage capacity, and can stillmaintain a good oxygen storage effect after high-temperature aging.

The invention discloses a preparation method for a palladium-doped cerium-zirconium composite oxide. The preparation method includes the following steps: cerium acetate and zirconium acetate are dissolved in deionized water, and a first mixed solution is obtained after uniform mixing; OP-10, P123 and n-butyl alcohol are respectively dripped into a solvent (methylbenzene), the mass ratio of the OP-10, the P123 and the n-butyl alcohol is 5-6 to 2-3 to 10-15, and a second mixed solution II is obtained after uniform mixing; the first mixed solution and the second mixed solution are mixed and stirred at a high speed to obtain a mixed emulsion; 2 weight percent palladium acetate is dripped in the mixed emulsion, and the mixture is stirred uniformly; 20 weight percent ammonium hydroxide is prepared to serve as a precipitator; the mixed emulsion and the precipitator (the 20 weight percent ammonium hydroxide) are then mixed, the mixture is stirred at a high speed for 2 to 3 hours and then stands for 12 to 24 hours within a temperature range of 40 to 50 DEG C, and a dirty solution is obtained; the dirty solution goes through high-speed centrifugal separation and suction filtration, and obtained solid phase matters are dried within a temperature range of 100 to 120 DEG C and calcined within a temperature range of 400 to 500 DEG C to obtain the palladium-doped nanometer cerium-zirconium composite oxide. The palladium-doped cerium-zirconium composite oxide prepared through the method has the characteristics of small particle diameter (the diameter can reach the nanometer level), large specific surface area and oxygen storage capacity, high oxygen storage and discharge rates, and high sintering resistance.

The invention relates to the technical field of catalysts, in particular to a ternary catalyst and a preparation method and application thereof. The preparation method of the ternary catalyst comprises the following steps of: step 1, mixing aqueous solution containing a manganese compound, aqueous solution containing an iron compound and aqueous solution containing a cerium compound to obtain precursor solution; step 2, soaking a modified gamma-Al2O3 pellet in precursor solution, and respectively drying and roasting to obtain the ternary catalyst. The preparation method adopts an immersion roasting method, which is simple to operate, and can ensure that three metal oxides of manganese, iron and cerium can be stably attached to the surface of the gamma-Al2O3 pellet and the prepared ternarycatalyst is high in catalytic activity, and problems that the existing preparation method of the ternary catalyst is complex and the catalytic effect of the prepared ternary catalyst is low are solved.

The invention relates to a solid solution supported catalyst, and in particular to a preparation method of a cerium-aluminum composite oxide with low cost and large specific surface area. The preparation method is characterized by comprising the following steps: (1) adding alumina hydrate in 100-170g/L of a cerium chloride aqueous solution, pulping to obtain a mixed liquid, adding 0.1-1 percent of a surfactant (by weight percentage) of the mixed liquid, uniformly stirring, putting the mixed liquid in a constant-temperature tank, and standing for 1-2h; (2) adding ammonia water or ammonium carbonate in a feed solution subjected to treatment in the first step, and controlling a pH value to be 8-10 to obtain gelatinous precipitates; (3) washing the gelatinous precipitates obtained in the second step with deionized water, and carrying out dehydration; (4) putting a product obtained through dehydration in the third step in a kiln, and roasting the product under the condition with the temperature being 500-700 DEG C for 4-6h; and (5) grinding the product subjected to roasting until the maximum particle size is 10 microns to obtain the cerium-aluminum composite oxide with large specific surface area. The preparation method is low in cost of raw materials and simple in technological process and is beneficial to large scale industrial production.

The invention provides a cerium-zirconium composite oxide which comprises a cerium-containing oxide, a zirconium-containing oxide and at least one oxide, wherein the oxide is selected from rare-earthmetallic elements except cerium; the content of the oxide which is selected from rare-earth metallic elements except cerium is 10-20wt%; after 4-8 hours of thermal treatment at 950 DEG C, the composite oxide has a pore volume of 0.30-0.60ml/g, a specific surface area of 58-100m<2>/g and an oxygen storage amount of 1.00mmol[O]/g at least. The cerium-zirconium composite oxide provided by the invention has a large pore volume structure, has a remarkable oxygen storage capability, and has a very good oxygen storage effect after high-temperature aging.

The invention discloses a novel motorcycle catalyst. The catalyst comprises a carrier, and an inner layer slurry and an outer layer slurry which are coated on the carrier; the inner layer slurry comprises, by mass, 20-50% of Al2O3, 30-60% of CeZrO2, 2-10% of a cerium precursor (by CeO2), 2-10% of a zirconium precursor (by ZrO2) and 2-10% of a vanadium precursor (by BaO); and the outer layer slurrycomprises, by mass, 30-60% of Al2O3, 30-50% of a CeZrO2 complex oxide, 2-10% of the cerium precursor (by CeO2), 2-10% of the zirconium precursor (by ZrO2) and 2-10% of the vanadium precursor (by BaO). The novel motorcycle catalyst can effectively reduce the content of motor emissions, prevent the pollution of the motor emissions to the environment and improve the air quality of the environment.

A core-shell oxide material comprises: a core which comprises a ceria-zirconia based solid solution powder having at least one ordered phase of a pyrochlore phase and a κ phase; and a shell which comprises an alumina based oxide disposed on at least a portion of a surface of the core.