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CN-122006726-A - Uranium oxide solid catalyst, preparation method and application

CN122006726ACN 122006726 ACN122006726 ACN 122006726ACN-122006726-A

Abstract

The invention discloses a uranium oxide solid catalyst, a preparation method and application thereof, wherein hydrogen peroxide is used as a precipitator to prepare uranium peroxide precursor, alkali precursors such as potassium nitrate and the like are used for soaking and roasting to prepare uranium oxide solid alkali, mesoporous silica is used as a carrier, and ammonia water is used for inducing an internal hydrolysis method and the alkali precursors to soak and roasting to prepare high-dispersion alkaline adjustable uranium oxide solid alkali with large specific surface area, so that the reaction which cannot be catalyzed by the traditional catalyst is realized.

Inventors

  • ZHAO YUBAO
  • Qu Baorui
  • Xie Shuaijie
  • LIU LU

Assignees

  • 南华大学

Dates

Publication Date
20260512
Application Date
20250926

Claims (7)

  1. 1. The preparation method of the uranium oxide solid catalyst is characterized by comprising the following steps of: S1, dissolving uranyl acetate solid powder in deionized water to obtain a transparent solution; S2, adding hydrogen peroxide or mesoporous silica into the obtained transparent solution, and drying the solid at 80 ℃ for 10-12 hours through solid-liquid separation to obtain the uranium oxide solid catalyst.
  2. 2. The method for preparing the uranium oxide solid catalyst according to claim 1, wherein in the step S2, 30% H 2 O 2 solution is added into the transparent solution, after stirring for 4 hours, washing and solid-liquid separation are carried out, the obtained solid is dried overnight at 80 ℃, and uranium peroxide solid powder is obtained after grinding.
  3. 3. A process for preparing uranium oxide solid catalyst according to claim 2, wherein 0.01g-0.02g KNO 3 dissolved in ionized water is weighed, 1g uranium peroxide solid powder is added, stirring is carried out for 1h, rotary evaporation is carried out at 50 ℃, the obtained solid is dried in an oven for 15h, then the obtained solid is placed in a muffle furnace, the temperature is raised to 500 ℃ at a temperature rising rate of 5 ℃ per min, and the solid is baked at constant temperature for 5h, thus obtaining the solid base catalyst.
  4. 4. The method for preparing a uranium oxide solid catalyst according to claim 1, wherein the uranium silicon atomic ratio=0.144, mesoporous silica is added to the transparent solution in the step S2, water is removed at 50 ℃ in a rotary evaporator after stirring for 3 hours, the obtained solid powder is ground and then is put into a 10mL glass bottle, 10mL of 25% concentrated ammonia water and 10mL of deionized water are added into a polytetrafluoroethylene lining, the glass bottle filled with the solid powder is put into the polytetrafluoroethylene lining, the solid powder is not contacted with the ammonia water, the solid powder is dried at 80 ℃ for 15 hours after being kept at 0.5 hours under hydrothermal condition at 60 ℃, and the high-dispersion uranium oxide is obtained by roasting at 500 ℃ for 5 hours under air atmosphere conditions, abbreviated as HDU.
  5. 5. A preparation method of a uranium oxide solid catalyst according to claim 4, wherein 0g-0.1g of alkali precursor is weighed and dissolved in deionized water to obtain KNO 3 solution, 0.5g of HDU precursor is added into KNO 3 solution, mixed and stirred to ensure that the HDU precursor is completely dispersed in KNO 3 solution, then the mixture is subjected to rotary evaporation at 50 ℃ and drying at 80 ℃ for 15 hours, and the obtained solid is ground into fine powder, heated to 500 ℃ at a heating rate of 10 ℃ per minute in inert atmosphere and baked in situ for 2 hours to obtain uranium oxide solid alkali with different loads and high dispersion states.
  6. 6. A uranium oxide solid catalyst, characterized in that the catalyst is obtained by the preparation method according to any one of claims 1 to 7.
  7. 7. The application of the uranium oxide solid catalyst is characterized in that the catalyst is prepared by the method of claim 6 and is applied to typical base-catalyzed isopropanol dehydrogenation and 1-hexene double-bond isomerization reactions.

Description

Uranium oxide solid catalyst, preparation method and application Technical Field The invention relates to the technical field of catalysts, in particular to a uranium oxide solid catalyst, a preparation method and application. Background The alkaline sites of the solid base are mainly from the strong alkaline substances produced by the decomposition of supported alkali metals, alkali metal amides, alkali metal or alkaline earth metal oxides, hydroxides and carbonates at high temperatures. If MgO itself is a solid base with strong alkalinity, alkali metal is loaded on the surface of MgO to generate strong alkalinity sites, alkali metal hydroxide treatment gamma-Al 2O3 forms aluminate with disordered crystal structure, cation vacancies existing on the aluminate surface are occupied by subsequently added alkali metal, meanwhile, the alkali metal is ionized, electrons are injected to oxygen atoms near the vacancies, and then the oxygen atoms with more negative charges have enhanced electron donating ability, so that alkalinity is generated. Although the use of solid base as a catalyst is later than that of solid acid, there are few examples of successful application in industry, but the catalyst has the advantages of low preparation cost, convenient activation and large surface area after mesoporous material is loaded. Uranium-containing catalysts have been studied since the 20 th century, 20. Uranium oxides and other uranium-containing compounds may be used either alone as catalysts or as promoters or supports for other metals or oxides. The uranium-containing catalyst is applied to various catalytic reactions due to good thermal stability, toxicity resistance and the like, and can catalyze reactions which are difficult to catalyze by some conventional materials, and the catalytic activity of the pure uranium oxide is limited by the small surface area and pore size, so that the increase of the surface area and the catalytic activity by loading mesoporous silica are very significant. Disclosure of Invention The invention aims to provide a uranium oxide solid catalyst, a preparation method and application thereof, and solves the problem of low catalytic activity of uranium oxide in the prior art. The invention is realized in such a way that the preparation of uranium oxide solid alkali with adjustable fecal alkalinity comprises the following steps: A. preparing a uranium peroxide precursor, dissolving certain mass of uranyl acetate solid powder into deionized water, continuously stirring for 1h, dropwise adding 30% H 2O2 solution, stirring for 4h again, performing solid-liquid separation, and drying at 80 ℃ to obtain uranium oxide solid powder. B. weighing 0.01g of KNO 3 dissolved deionized water according to the load capacity of 1%, adding 1g of uranium peroxide precursor to dissolve in KNO 3 solution, performing rotary evaporation at 50 ℃, drying the obtained solid in an oven, grinding, placing the obtained solid powder in a muffle furnace, raising the temperature to 500 ℃ at the temperature rising rate of 5 ℃ per minute, and performing constant-temperature roasting for 5 hours, wherein the obtained solid base catalyst is recorded as 1K/U. C. In the same way, KNO 3 solid with the mass percent of 2 of uranium peroxide is weighed to prepare a solution, and the solution is stirred and steamed in a rotary way to prepare 2K/U solid alkali. D. A batch of catalyst xK/U (x is KNO 3 loading) was prepared in the same way. The uranium peroxide precursor which is not treated by KNO 3 is heated to 500 ℃ at a temperature rising rate of 5 ℃ per minute, and is placed in a muffle furnace for roasting for 5 hours, so that a control sample UO 3 is obtained. The invention further adopts the technical scheme that: The preparation of the high-dispersion uranium oxide solid base comprises the following steps: E. In step A, 30% H 2O2 solution was changed to SBA-15, and the mixture was put into uranyl acetate solution, magnetically stirred at 35℃for 3 hours, then spin-distilled at 50℃and the resulting solid was dried in an oven at 80℃overnight. Grinding and then filling into a 10mL glass bottle, adding 10mL of 25% concentrated ammonia water and 10mL of deionized water into the polytetrafluoroethylene lining, and placing the glass bottle filled with solid powder into the polytetrafluoroethylene lining, wherein the solid powder is not contacted with the ammonia water. The hydrothermal temperature is 60 ℃ and kept for 0.5h. Drying at the temperature of 80 ℃ for 15 hours, and roasting at the temperature of 500 ℃ for 5 hours in the atmosphere of air in a muffle furnace to obtain the uranium oxide in a high dispersion state, abbreviated as HDU. F. Based on 15% loading, 0.075g of base precursor was accurately weighed and dissolved in deionized water to give KNO 3 solution. Adding 0.5g of HDU precursor into the solution, mixing and stirring for 1h to ensure that the HDU precursor is completely dispersed in KNO 3 solution, performing rotary ev