IPC분류정보
국가/구분 |
United States(US) Patent
등록
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국제특허분류(IPC7판) |
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출원번호 |
US-0905085
(2004-12-14)
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발명자
/ 주소 |
- Wang,Feng Yun
- Cheng,Soofin
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출원인 / 주소 |
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
9 인용 특허 :
6 |
초록
▼
A method for the preparing pure, thermally stable and high surface area ceria is described, wherein the ceria maintains a surface area of 12 m2/g after calcination at 980째 C. in air for 4 hours. In the method, an aqueous solution containing Ce3+, Mg2+ , organic acid and organic polymer is prepared
A method for the preparing pure, thermally stable and high surface area ceria is described, wherein the ceria maintains a surface area of 12 m2/g after calcination at 980째 C. in air for 4 hours. In the method, an aqueous solution containing Ce3+, Mg2+ , organic acid and organic polymer is prepared and then evaporated to obtain a gel. The gel is calcined to obtain a mixed oxide, and then MgO is leached from the mixed oxide with a solvent to obtain raw ceria. The raw ceria is then washed, filtered and dried to obtain a ceria product.
대표청구항
▼
What is claimed is: 1. A method for the preparing ceria of high surface area, comprising: preparing an aqueous solution containing Ce3+, Mg 2+, organic acid and organic polymer; evaporating the aqueous solution to obtain a gel; calcining the gel to obtain a mixed oxide; leaching MgO from the mixed
What is claimed is: 1. A method for the preparing ceria of high surface area, comprising: preparing an aqueous solution containing Ce3+, Mg 2+, organic acid and organic polymer; evaporating the aqueous solution to obtain a gel; calcining the gel to obtain a mixed oxide; leaching MgO from the mixed oxide with a solvent to obtain raw ceria; and cleaning the raw ceria to obtain a ceria product. 2. The method of claim 1, wherein the aqueous solution containing Ce3+ and Mg2+ is prepared with a cerium precursor and a magnesium precursor selected from the group consisting of chloride, nitrate, sulfate, acetate, oxalate and citrate salts of cerium and magnesium. 3. The method of claim 1, wherein the aqueous solution containing Ce3+ and Mg2+ is prepared with a cerium precursor and a magnesium precursor selected from the group consisting of nitrate and acetate salts of cerium and magnesium. 4. The method of claim 1, wherein the aqueous solution containing Ce3+ and Mg2+ is prepared with cerium nitrate and magnesium nitrate. 5. The method of claim 1, wherein the molar ratio of Ce+3 to Mg+2 in the aqueous solution is adjusted so that composition of the mixed oxide is Ce1-xMgxO2-d, x is from 0.1 to 0.7 and 2-d varies with the amount of Ce+3 and Ce+4 in the mixed oxide to keep charge balance. 6. The method of claim 1, wherein the molar ratio of Ce+3 to Mg+2 in the aqueous solution is adjusted so that composition of the mixed oxide is Ce1-xMgxO2-d, x is from 0.3 to 0.7 and 2-d varies with the amounts of Ce+3 and Ce+4 in the mixed oxide to keep charge balance. 7. The method of claim 1, wherein the molar ratio of Ce+3 to Mg+2 in the aqueous solution is adjusted so that composition of the mixed oxide is Ce0.5Mg0.5O2-d, 2-d varies with the amounts of Ce+3 and Ce+4 in the mixed oxide to keep charge balance. 8. The method of claim 1, wherein the organic acid is selected from the group consisting of acetic acid, citric acid and glycine. 9. The method of claim 1, wherein the organic acid is citric acid. 10. The method of claim 1, wherein the organic polymer comprises polyethylene glycol (PEG) with molecular weight of 600-10000. 11. The method of claim 1, wherein the step of evaporating the aqueous solution is conducted at temperature of 30-110째 C. 12. The method of claim 1, wherein the step of calcining the gel is conducted at temperature of 400-1000째 C. 13. The method of claim 1, wherein the step of leaching MgO is carried out at 15-70째 C. with a solvent selected from the group consisting of nitric acid of 0.1-5 wt %, NH4Cl solution of 1-10 wt %, acetic acid solution of 1-20 wt % and HCl solution of 0.1-5 wt %.
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