Search

CN-117566782-B - Method for synthesizing cerium oxide at low temperature

CN117566782BCN 117566782 BCN117566782 BCN 117566782BCN-117566782-B

Abstract

The invention provides a method for synthesizing cerium oxide at low temperature. The method for synthesizing the cerium oxide at low temperature comprises the following steps of (1) dissolving Ce (NO 3 ) 3 ·6H 2 O) in a solvent at room temperature, adding C 2 H 10 N 6 H 2 CO 3 , stirring to obtain a precursor 1, (2) centrifuging the precursor 1, taking out precipitates, washing to obtain a precursor 2, and (3) drying the precursor 2 at 115-130 ℃ for 24-26 hours to obtain the cerium oxide.

Inventors

  • XU YAOHUI
  • YUAN LI
  • PENG WANXIN
  • GONG JIANCHUN
  • MA ZHENHUI
  • CAO FENGHONG
  • WANG QIN

Assignees

  • 乐山师范学院

Dates

Publication Date
20260512
Application Date
20231129

Claims (7)

  1. 1. A method for synthesizing cerium oxide at low temperature, which is characterized by comprising the following steps: (1) At room temperature, ce (NO 3 ) 3 ·6H 2 O is dissolved in a solvent, then C 2 H 10 N 6 H 2 CO 3 is added, and the mixture is stirred to obtain a precursor 1; (2) Centrifuging the precursor 1, taking precipitate and washing to obtain a precursor 2; (3) Drying the precursor 2 at 115-130 ℃ for 24-26 hours to obtain cerium oxide; In the step (1), the mass ratio of Ce (NO 3 ) 3 ·6H 2 O、C 2 H 10 N 6 H 2 CO 3 to water) is 1 (1.7-2) to 15, and the solvent is distilled water.
  2. 2. The method for synthesizing cerium oxide at a low temperature according to claim 1, wherein the stirring time in the step (1) is 22-26.5 hours.
  3. 3. The method for synthesizing cerium oxide at a low temperature according to claim 2, wherein the stirring in the step (1) comprises the steps of stirring for 15min until the color of the system changes, and continuing stirring for 24h.
  4. 4. The method for synthesizing cerium oxide at a low temperature according to claim 1, wherein the centrifugal speed in the step (2) is 4000-5000 rpm, the centrifugal time is 8-12 min, and the washing is 3-5 times of washing with distilled water.
  5. 5. The method for synthesizing cerium oxide at a low temperature according to claim 4, wherein the centrifugal speed in the step (2) is 4500rpm, the centrifugal time is 10min, and the washing is performed 3 times with distilled water.
  6. 6. The method for synthesizing cerium oxide at a low temperature according to claim 1, wherein the drying temperature in the step (3) is 120℃and the drying time is 24 hours.
  7. 7. The cerium oxide synthesized by the method for synthesizing cerium oxide at a low temperature according to any one of claims 1 to 6.

Description

Method for synthesizing cerium oxide at low temperature Technical Field The invention belongs to the technical field of synthesis of cerium oxide, and particularly relates to a method for synthesizing cerium oxide at a low temperature. Background Cerium oxide (CeO 2) has been attracting attention in many fields due to its abundant reserves, low cost, unique crystal structure, and reversible conversion between Ce 3+ and Ce 4+. The nano CeO 2 has unique physical and chemical characteristics due to surface effect, volume effect, quantum size effect and macroscopic tunnel effect, is widely applied to the fields of precision ceramics, magnetic recording, ultraviolet shielding, photoelectric sensing, catalysis and the like, and particularly has important application value in the fields of CO catalytic oxidation, organic synthesis catalysis, photocatalysis, adsorption, biological antioxidation and the like due to the excellent oxidation-reduction capability of the nano CeO 2 in the catalysis field. The synthesis method of CeO 2 not only can influence the morphology and the size of the CeO 2, but also can influence the application characteristics of the CeO 2. At present, three types of reagents are mainly needed in the synthesis process of CeO 2, namely a cerium source, most of cerium nitrate or cerium chloride (in +3 valence state), a precipitator for precipitation/crystallization of Ce 3+ ions in aqueous solution, mainly potassium hydroxide and sodium hydroxide (belonging to strong base), ammonia water, urea, ammonium carbonate and ammonium bicarbonate (belonging to weak base), and an oxidant for realizing phase transformation of Ce 3+ phase to Ce 4+, and hydrogen peroxide (H 2O2) is the most. For precipitating agent, strong alkali has strong corrosiveness, and weak alkali is easy to volatilize, for oxidizing agent, H 2O2 is category 5 oxidizing agent and category 8 corrosives, belongs to explosive strong oxidizing agent, has strong volatility, and has great harm to skin, respiratory tract and the like. In addition, some synthesis processes can obtain CeO 2 phase by high-temperature roasting process, which clearly further increases energy consumption. Disclosure of Invention The invention aims to solve the problems of complex raw materials, low safety, complex process and high energy consumption in the cerium oxide synthesis process by providing a low-temperature cerium oxide synthesis method. The technical proposal adopted for solving the technical problems is to provide a method for synthesizing cerium oxide at low temperature, which comprises the following steps: (1) At room temperature, ce (NO 3)3·6H2 O is dissolved in a solvent, then C 2H10N6H2CO3 is added, and the mixture is stirred to obtain a precursor 1; (2) Centrifuging the precursor 1, taking precipitate and washing to obtain a precursor 2; (3) And drying the precursor 2 at 115-130 ℃ for 24-26 hours to obtain the cerium oxide. The preparation method has the beneficial effects that Ce (NO 3)3·6H2 O is used as a cerium source, C 2H10N6H2CO3 is used as a precipitator to realize crystallization and precipitation of Ce 3+ in aqueous solution, meanwhile, C 2H10N6H2CO3 is used as a guanidino compound, can form a hydrogen bond complex with various oxo cations and can be used as an acceptor of an oxo anion object, in the reaction process, water molecules are continuously stirred to generate an electrostatic effect under the action of water force, so that oxygen molecules in the air are excited by charges to form oxo anions, the oxo anions can activate oxygen molecules in the air, and in the reaction process of Ce (NO 3)3·6H2 O and C 2H10N6H2CO3), C 2H10N6H2CO3 is complexed with NO 3- to form an oxidizing compound to promote conversion of Ce 3+ to Ce (OH) 4, and Ce (OH) 4 is dried to form cerium dioxide more completely. Preferably, in the step (1), the mass ratio of Ce (NO 3)3·6H2O、C2H10N6H2CO3 to water is 1 (1.7-2): 15, and the solvent is distilled water. Preferably, in the step (1), the stirring time is 22-26.5 h. More preferably, the stirring in the step (1) comprises the steps of stirring for 15min until the color of the system changes, and continuing stirring for 24h. Preferably, in the step (2), the centrifugal speed is 4000-5000 rpm, the centrifugal time is 8-12 min, and the washing is carried out 3-5 times by using distilled water. Preferably, in the step (2), the centrifugal speed is 4500rpm, the centrifugal time is 10min, and the washing is performed 3 times by distilled water. Preferably, the drying temperature in step (3) is 120 ℃ and the drying time is 24 hours. The invention also provides the cerium oxide synthesized by the method. The invention has the following beneficial effects: (1) The invention uses C 2H10N6H2CO3 as a precipitator, does not need to additionally add an oxidant and other reaction auxiliary agents, has soft reaction process, does not generate a large amount of gas, has low volatility and generates less pollution. (2) The invent