CN-121244217-B - Preparation method and application of trans-cerium dioxide-nickel catalyst

Abstract

The invention belongs to the technical field of metal catalysts, and particularly relates to a preparation method and application of a trans-cerium dioxide-nickel catalyst. Mixing nickel nitrate, polyvinylpyrrolidone, glycol, urea and water, performing hydrothermal reaction, separating to obtain a reaction product, washing, drying, calcining and cooling the reaction product to obtain a catalyst precursor, adding water into the catalyst precursor to disperse to obtain turbid liquid, adding cerium nitrate into the turbid liquid to dissolve, heating to obtain a solid product, calcining the solid product, cooling and performing reduction reaction to obtain the trans-cerium oxide-nickel catalyst. The trans-cerium dioxide-nickel catalyst uses CeO 2 as a metal active site, ni as a catalyst carrier, solves the problems of oxygen vacancy reduction and oxygen storage/release capacity degradation caused by the fact that the crystal grain grows and the structure tends to be perfect and stable at high temperature of the traditional large-size CeO 2 , exerts an excellent catalytic effect with a small content of Ce, and has important significance for the utilization of rare earth resources.

Inventors

• HU JUNHAO
• YU WENZHU

Assignees

• 山东理工大学

Dates

Publication Date

20260508

Application Date

20251203

Claims (9)

1. 1. The application of a trans-cerium oxide-nickel catalyst in methane carbon dioxide dry reforming is characterized in that the trans-cerium oxide-nickel catalyst takes CeO 2 as a metal active site and Ni as a catalyst carrier, and the preparation method of the trans-cerium oxide-nickel catalyst comprises the following steps: (1) Mixing nickel nitrate, polyvinylpyrrolidone, glycol, urea and water, performing hydrothermal reaction, and separating to obtain a reaction product; (2) Washing, drying, calcining and cooling the reaction product to obtain a catalyst precursor; (3) Adding water into the catalyst precursor for dispersion to obtain turbid liquid, adding cerium nitrate into the turbid liquid for dissolution, and heating to obtain a solid product; (4) Calcining the solid product, cooling, and carrying out reduction reaction to obtain a trans-cerium oxide-nickel catalyst; The mass of cerium element in the cerium nitrate in the step (3) is 1-10% of the mass of the catalyst precursor; The reduction reaction temperature in the step (4) is 550-650 ℃, and the particle size of CeO 2 in the trans-cerium oxide-nickel catalyst is 6.56-18.18nm.
2. 2. The use of a trans-ceria-nickel catalyst according to claim 1 in the dry reforming of methane carbon dioxide, wherein the molar ratio of nickel nitrate to the total volume of water and ethylene glycol in step (1) is 1:11-15, wherein the total volume of water and ethylene glycol is L in mol.
3. 3. The use of a trans-ceria-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, wherein the volume ratio of water to ethylene glycol in step (1) is 1:0.5-0.75, and the ratio of nickel nitrate, polyvinylpyrrolidone and urea is 1:250-300:300-350, wherein nickel nitrate is calculated in mol, and both polyvinylpyrrolidone and urea are calculated in g.
4. 4. The use of a trans-ceria-nickel catalyst according to claim 1 for the dry reforming of methane carbon dioxide, characterized in that the hydrothermal reaction temperature in step (1) is 160-240 ℃ and the hydrothermal reaction time is 12-24 hours.
5. 5. Use of a trans-ceria-nickel catalyst according to claim 1 in the dry reforming of methane carbon dioxide, characterized in that in step (2) the drying temperature is 60-80 ℃ and the drying time is 12-14 hours.
6. 6. The use of a trans-ceria-nickel catalyst according to claim 1 in the dry reforming of methane carbon dioxide, characterized in that in step (2) the calcination temperature is 400-500 ℃ and the calcination time is 2-4 hours.
7. 7. The use of a trans-ceria-nickel catalyst according to claim 1 for the dry reforming of methane carbon dioxide, characterized in that the heating temperature in step (3) is 70-90 ℃ and the heating time is 3-5 hours.
8. 8. The use of a trans-ceria-nickel catalyst according to claim 1 in the dry reforming of methane carbon dioxide, characterized in that in step (4) the calcination temperature is 400-500 ℃ and the calcination time is 2-4 hours.
9. 9. The use of the trans-ceria-nickel catalyst according to claim 1 for dry reforming of methane and carbon dioxide, wherein the reduction reaction atmosphere in step (4) is a hydrogen atmosphere, and the reduction reaction time is 1.5 to 2.5 hours.

Description

Preparation method and application of trans-cerium dioxide-nickel catalyst Technical Field The invention belongs to the technical field of metal catalysts, and particularly relates to a preparation method and application of a trans-cerium dioxide-nickel catalyst. Background The core of the dry reforming reaction of methane and carbon dioxide is that two greenhouse gases of methane and carbon dioxide are converted into synthesis gas (H 2 +CO) under the action of a high-temperature catalyst, and the reaction has the dual values of emission reduction and resource production, and is one of key technologies for coping with energy crisis and greenhouse effect. The core background requirement of the methane and carbon dioxide dry reforming reaction is derived from two points, namely that CH 4 and CO 2 generated by fossil energy consumption are discharged to exacerbate global warming and a high-efficiency conversion path is needed, and the synthesis gas can be used for further preparing chemical raw materials such as methanol and olefin, so that carbon recycling utilization is realized. The traditional nickel-cerium oxide catalyst is paid attention to because of good catalytic performance and stability, but with the deep research, the defects of the traditional nickel-cerium oxide catalyst are gradually revealed that firstly, the catalyst is sintered and deactivated, ni nano particles are easy to agglomerate and grow (namely, sinter) at high temperature, so that the number of active sites is rapidly reduced, the catalyst is rapidly deactivated, secondly, the serious carbon deposition problem is solved, CH 4 is cracked on the surface of Ni, carbon species (such as carbon deposition and carbon fibers) are easy to generate, the carbon can cover the active sites and block a catalyst pore channel, so that the catalyst is directly deactivated in a poisoning way, thirdly, ceO 2 is poor in carrier stability, ceO 2 is easy to generate crystal grain growth at high temperature, and the oxygen storage/release capacity of the catalyst is remarkably reduced, so that the overall performance of the catalyst is further weakened. Chinese patent CN114733528A discloses a preparation method and application of a nickel/cerium oxide catalyst, wherein cerium salt solution and alkaline precipitant solution are mixed at room temperature, stirred for 10-30min and then transferred to a reaction kettle for reaction, the obtained product A is washed by deionized water, centrifuged and dried to obtain a basic cerium carbonate precursor, the basic cerium carbonate precursor is dissolved in sodium hydroxide solution at room temperature, nickel salt solution is slowly dripped, the dripping is continued for 30-40min, ageing is carried out for 2-4 days at 20-25 ℃ to obtain a product B, and the product B is sequentially washed, centrifuged, dried in vacuum and roasted to obtain the nickel/cerium oxide catalyst. Disclosure of Invention The invention aims to provide a preparation method of a trans-cerium oxide-nickel catalyst, which has excellent catalytic activity and thermal stability, and simultaneously provides application of the trans-cerium oxide-nickel catalyst. The preparation method of the trans-cerium oxide-nickel catalyst comprises the following steps: (1) Mixing nickel nitrate, polyvinylpyrrolidone, glycol, urea and water, performing hydrothermal reaction, and separating to obtain a reaction product; (2) Washing, drying, calcining and cooling the reaction product to obtain a catalyst precursor; (3) Adding water into the catalyst precursor for dispersion to obtain turbid liquid, adding cerium nitrate into the turbid liquid for dissolution, and heating to obtain a solid product; (4) Calcining the solid product, cooling, and performing reduction reaction to obtain the trans-cerium oxide-nickel catalyst. The ratio of the mole number of the nickel nitrate to the total volume of the water and the glycol in the step (1) is 1:11-15, wherein the total volume of the nickel nitrate is calculated by mole, and the total volume of the water and the glycol is calculated by L. In the step (1), the volume ratio of water to glycol is 1:0.5-0.75, and the ratio of nickel nitrate, polyvinylpyrrolidone and urea is 1:250-300:300-350, wherein the nickel nitrate is calculated in mol, and the polyvinylpyrrolidone and the urea are calculated in g. The hydrothermal reaction temperature in the step (1) is 160-240 ℃ and the hydrothermal reaction time is 12-24 hours. The drying temperature in the step (2) is 60-80 ℃ and the drying time is 12-14 hours. In the step (2), the calcination temperature is 400-500 ℃, the calcination time is 2-4 hours, the temperature rising rate of calcination is 2-5 ℃ per minute, and the calcination is cooled to be naturally cooled to room temperature. In the step (3), the mass of cerium element in the cerium nitrate is 1-10% of the mass of the catalyst precursor, the heating temperature is 70-90 ℃, and the heating time is 3-5 hours. In the step