High-stability catalyst with yolk-shell structure as well as preparation method and application of high-stability catalyst

Abstract

In order to overcome the defects in the prior art, the invention provides a preparation method of a high-stability catalyst with an egg yolk-shell structure and application of the catalyst in preparation of DHA (Docosahexaenoic Acid) through catalytic oxidation of glycerol. The structure of the catalyst is Au / CuO (at) Viod (at) SiO2, and the catalyst is prepared by the following steps: sequentially mixing copper oxide with two groups of reactants, namely a precipitant, layered resin, a surfactant and a silicon source, then carrying out high-temperature reaction, carrying out high-temperature calcination to obtain an intermediate product, mixing the intermediate product with a gold source, then adding an extract of lilac leaves, carrying out reaction, and carrying out high-temperature calcination to obtain the catalyst. The relatively closed structure of the carrier is maintained through a high-temperature carbonization method, and the problems of catalyst deactivation and poor stability are solved while high catalytic activity and selectivity are maintained. In addition, a plant reduction method step is introduced, so that the selectivity of the obtained catalyst on a specific product obtained by catalytic oxidation of glycerol is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and particularly relates to a high-stability catalyst with an egg yolk-shell structure, a preparation method and an application thereof. Background Art

[0002] Biodiesel is considered the most effective alternative to fossil fuels, but the accumulation of its byproduct, glycerol, severely hinders its rapid development. Therefore, further conversion and processing of glycerol has become a crucial component of the biodiesel industry. Among the many value-added products from glycerol conversion, 1,3-dihydroxyacetone (DHA) is one of the most attractive high-value-added products obtained through the selective oxidation of glycerol. Therefore, the preparation of DHA through the selective oxidation of glycerol has important practical significance.

[0003] Currently, research on the catalytic oxidation of glycerol to produce DHA has generally encountered severe catalyst deactivation, poor recyclability, and instability. Furthermore, the catalysts used in previous studies often utilize chemical reagents as reducing or protective agents during the preparation process, which inevitably impacts the biocompatibility of DHA. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a high-stability catalyst with a yolk-shell structure. The catalyst has the structural formula: Au / CuO@Viod@SiO2.

[0005] Accordingly, the present invention also provides a method for preparing a high-stability catalyst having a yolk-shell structure with a structural formula of Au / CuO@Viod@SiO2, the method comprising the following steps:

[0006] Step 1: dispersing copper oxide in a first solvent at room temperature to obtain a mixture A;

[0007] Step 2: adding a precipitant and a layering resin to mixture A in a first stirring state at room temperature, and reacting for 16-20 hours to obtain mixture B;

[0008] Step 3: Add a surfactant and a silicon source to mixture B under a second stirring state at room temperature, and react for 4-8 hours to obtain mixture C;

[0009] Step 4: Separate the mixture C into solid and liquid, take the liquid phase, react at 100-120°C for 20-28h, and then cool to room temperature to obtain intermediate product D;

[0010] Step 5: washing and drying the intermediate product D to obtain the intermediate product E;

[0011] Step 6: calcining the intermediate product E at 450-550° C. in an air environment for 3-5 hours and cooling to room temperature to obtain the intermediate product F;

[0012] Step 7 dispersing the intermediate product F in the second solvent under the environment of 25-35℃, adding the gold source, and reacting for 4-12h under the third stirring condition of 25-35℃ to obtain the mixture G;

[0013] Step 8 maintaining the reaction condition of Step 7 unchanged, adding the extract of Syringa oblata Lindl. to the mixture G, and reacting for 4-8h to obtain the pre-product H;

[0014] Step 9 washing and drying the pre-product H to obtain the pre-product I;

[0015] Step 10 calcining the pre-product I in the air environment at 300-400℃ for 1-3h, and cooling to room temperature to obtain the high-stability catalyst with the yolk-shell structure.

[0016] Further, the copper oxide in Step 1 is prepared by the following method:

[0017] Step 101 respectively dehydrating the cupric chloride dihydrate, the sodium carbonate, and the sodium chloride under the high-temperature condition;

[0018] Step 102 putting 1-3 parts of the dehydrated cupric chloride, 1-3 parts of the sodium carbonate, 3-8 parts of the sodium chloride, and 0.1-0.3 parts of SBA-15 into a ball mill device for grinding to obtain a powdery product;

[0019] Step 103 calcining the powdery product obtained in Step 102 in the air environment at 450-550℃ for 1-3h to obtain a calcined product; when the calcination in Step 103 is performed, the heating rate is 4-8℃ / min;

[0020] Step 104 washing and drying the calcined product obtained in Step 103 to obtain the copper oxide.

[0021] Further, the first solvent in Step 1 is compounded by deionized water and anhydrous ethanol according to the volume ratio of deionized water:anhydrous ethanol=1:2-3.

[0022] Further, the addition amount of the first solvent in Step 1 is 900-1000 times of the addition amount of the copper oxide; the addition amount of the precipitant in Step 2 is 25-35 times of the addition amount of the copper oxide, and the addition amount of the layering resin is 1.2-12 times of the addition amount of the copper oxide; the addition amount of the surfactant in Step 3 is 1.2-6.8 times of the addition amount of the copper oxide, and the addition amount of the silicon source is 2-16 times of the addition amount of the copper oxide.

[0023] Further, when the calcination in Step 6 is performed, the heating rate is 3-6℃ / min; and when the calcination in Step 10 is performed, the heating rate is 1-3℃ / min.

[0024] Further, the stirring speed of the first stirring state is 100-300 r / min; the stirring speed of the second stirring state is 1000-3000 r / min; and the stirring speed of the third stirring state is 200-300 r / min.

[0025] Further, the second solvent in step 7 is deionized water, and the addition amount of the second solvent is 45-55 times of the addition amount of the intermediate product F.

[0026] Further, the addition amount of the gold source in step 7 is 58-60 mM per 1 g of the intermediate product F; and the addition amount of the plant leaf extract in step 8 is 1-3 mg / mL.

[0027] Optionally, the above-mentioned precipitant is preferably ammonia water.

[0028] Optionally, the above-mentioned layer-forming resin is preferably resorcinol-formaldehyde resin (RF). Compared with other resins, the layer formed by the RF resin can fill the gap between the template, form a uniform coating layer, maintain the template structure after carbonization, and form a hierarchical porous carbon material after removing the template. In addition, the RF resin can be combined with soft / hard templates (such as CTAB, SiO2 nanospheres) to form an ordered porous structure by sol-gel method or co-assembly, co-assembled with CTAB micelles to form a mesoporous carbon material suitable for gas diffusion or liquid phase reaction.

[0029] Optionally, the above-mentioned surfactant is one of cetyltrimethylammonium chloride, dodecyl dimethyl benzyl ammonium chloride, and cetyltrimethylammonium bromide. Preferably, it is cetyltrimethylammonium bromide (CTAB).

[0030] Optionally, the above-mentioned silicon source is one of tetraethyl orthosilicate, methyltrimethoxysilane, sodium silicate, methyltriethoxysilane, dimethyldiethoxysilane, and aminosilane. Preferably, it is tetraethyl orthosilicate (TEOS).

[0031] Optionally, the above-mentioned gold source is one of tetrachloroauric acid, potassium chloroaurate, sodium chloroaurate, and bromoauric acid. Preferably, it is tetrachloroauric acid.

[0032] In addition, the application also provides an application of the high-stability catalyst with the above-mentioned yolk-shell structure in the preparation of 1,3-dihydroxyacetone by catalytic oxidation of glycerol.

[0033] The application has at least one of the following advantages:

[0034] 1. The present application maintains the relative closed structure of the carrier by high-temperature carbonization method, which not only prevents the core particles from being released from the shell, but also allows small molecules to penetrate into the core particles through the shell, and there is a hollow space between the core particles and the shell, which can provide space for the free movement of the core particles. Therefore, the catalyst prepared by the present application not only maintains high catalytic activity and selectivity, but also overcomes the problems of catalyst deactivation and poor stability.

[0035] 2. The plant reduction method step is introduced in the method for preparing the catalyst of the present application, which not only significantly improves the selectivity of the obtained catalyst for catalyzing the oxidation of glycerol to obtain a specific product, but also better encapsulates the active component into the shell, effectively inhibits the migration, sintering and metal overflow of the active component, and is green and environmentally friendly.

[0036] 3. The catalyst preparation method of the present application is simple, low in cost and green, and is conducive to industrialization and large-scale application. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 TEM images and particle size distribution of Au / CuO@Viod@SiO2 catalysts prepared by different embodiments of the present application are shown, wherein: (a) Au / CuO@Viod@SiO2 catalyst prepared by Example 1, (b) Au / CuO@Viod@SiO2 catalyst prepared by Example 2, (c) Au / CuO@Viod@SiO2 catalyst prepared by Example 3, (d) Au / CuO@Viod@SiO2 catalyst prepared by Example 4.

[0038] Figure 2 TEM images and particle size distribution of Au / CuO@Viod@SiO2 catalysts prepared by Example 4 of the present application before and after recycling are shown, wherein: (a) fresh catalyst, (b) catalyst after five cycles. DETAILED DESCRIPTION

[0039] The present application will now be further described in detail in conjunction with the accompanying drawings.

[0040] Example 1

[0041] (1) Mechanical method for preparing CuO: First, CuCl2.2H2O, NaCO3, NaCl were treated by dehydration at 170°C for 14h, then 2g CuCl2, 2g Na2CO3, 12g NaCl, 0.4g SBA-15 and 243g zirconia grinding balls (grinding ball mass: material mass = 15:1) were ground in a zirconia tank, after 30min, the solid powder was collected and calcined at 500°C for 2h in a muffle furnace at a rate of 5°C / min, after which the filter cake was washed with a large amount of deionized water and dried at 60°C for 12h. The product obtained was CuO.

[0042] (2) One-pot method for preparing CuO@Viod@SiO2 carrier: 0.25g of CuO was ultrasonically dispersed in 80mL of water and 202.5mL of anhydrous ethanol, 7.5g of ammonia water and 1.4g of RF precursor were added successively under continuous stirring, after 18h of reaction, 1.64g of CTAB and 2.33g of TEOS were added under vigorous stirring and the reaction was continued for 6h, the reaction liquid was collected in a polytetrafluoroethylene liner in a stainless steel reaction kettle at 100°C for 24h, then cooled to room temperature. Washed with a large amount of deionized water, the filter cake was dried at 60°C for 24h, and finally calcined at 500°C for 5h under air atmosphere, controlling the heating rate at 5°C / min. After high-temperature carbonization, the CuO@Viod@SiO2 yolk-shell structure carrier was obtained.

[0043] (3) Plant reduction method for preparing Au / CuO@Viod@SiO2 catalyst: 0.99g of CuO@Viod@SiO2 carrier was dispersed in 50mL of deionized water at 30°C, 1.04mL of 58.56mM HAuCl4 solution was added, and after stirring at 30°C for 4h, 2mg / mL of lilac leaf extract was added, and the stirring was continued for 4h. After the reaction was completed, the filter cake was obtained by filtration, dried at 60°C for 12h, and finally calcined at 350°C for 2h under air atmosphere, controlling the heating rate at 2°C / min, to obtain the final product Au / CuO@Viod@SiO2 catalyst.

[0044] Example 2

[0045] (1) Mechanical method for preparing CuO: First, CuCl2.2H2O, NaCO3, NaCl were treated by dehydration at 170°C for 14h, then 2g CuCl2, 2g Na2CO3, 12g NaCl, 0.4g SBA-15 and 243g zirconia grinding balls (grinding ball mass: material mass = 15:1) were ground in a zirconia tank, after 30min, the solid powder was collected and calcined at 500°C for 2h in a muffle furnace at a rate of 5°C / min, after which the filter cake was washed with a large amount of deionized water and dried at 60°C for 12h. The product obtained was CuO.

[0046] (2) One-pot preparation of CuO@Void@SiO2 support: 0.25 g of CuO was ultrasonically dispersed into 80 mL of water and 202.5 mL of anhydrous ethanol. 7.5 g of ammonia water and 1.4 g of RF precursor were added successively under continuous stirring. After 18 h of reaction, 1.64 g of CTAB and 1.17 g of TEOS were added under vigorous stirring and the reaction was continued for another 6 h. The reaction solution was collected in a polytetrafluoroethylene liner in a stainless steel reactor and reacted at 100 °C for 24 h. Then it was cooled to room temperature. It was washed with a large amount of deionized water, and the filter cake was dried at 60 °C for 24 h. Finally, it was calcined at 500 °C for 5 h under air atmosphere (the heating rate was 5 °C / min). After high-temperature carbonization, the CuO@Void@SiO2 yolk-shell structure support was obtained.

[0047] (3) Preparation of Au / CuO@Void@SiO2 catalyst by plant reduction method: 0.99 g of CuO@Void@SiO2 support was dispersed in 50 mL of deionized water at 30 °C, and 1.04 mL of 58.56 mM HAuCl4 solution was added. After stirring at 30 °C for 4 h, 2 mg / mL of lilac leaf extract was added, and the stirring was continued for another 4 h. After the reaction was completed, it was washed several times with deionized water. The filter cake was obtained by filtration, dried at 60 °C for 12 h, and finally calcined at 350 °C for 2 h under air atmosphere (the heating rate was 2 °C / min). The final product, Au / CuO@Void@SiO2 catalyst, was obtained.

[0048] Example 3

[0049] (1) Mechanical preparation of CuO: CuCl2·2H2O, NaCO3, and NaCl were first dehydrated at 170 °C for 14 h. Then 2 g of CuCl2, 2 g of Na2CO3, 12 g of NaCl, 0.4 g of SBA-15, and 243 g of zirconia grinding balls (grinding ball mass: material mass = 15:1) were ground in a zirconia jar. After 30 min, the solid powder was collected and calcined at 500 °C for 2 h with a heating rate of 5 °C / min in a muffle furnace. After washing with a large amount of deionized water, the filter cake was dried at 60 °C for 12 h. The product obtained was CuO.

[0050] (2) One-pot synthesis of CuO@Viod@SiO2 support: 0.25 g of CuO was dispersed in 80 mL of water and 202.5 mL of absolute ethanol under ultrasonication. 7.5 g of ammonia water and 1.4 g of RF precursor were added successively under continuous stirring. After 18 h of reaction, 0.54 g of CTAB and 1.17 g of TEOS were added under vigorous stirring and the reaction was continued for another 6 h. The reaction solution was collected in a polytetrafluoroethylene liner in a stainless steel reactor and reacted at 100 °C for 24 h. After cooling to room temperature, the product was washed with a large amount of deionized water, dried at 60 °C for 24 h, and finally calcined at 500 °C for 5 h under air atmosphere (heating rate of 5 °C / min). After high-temperature carbonization, the CuO@Viod@SiO2 yolk-shell structured support was obtained.

[0051] (3) Plant reduction method for preparing Au / CuO@Viod@SiO2 catalyst: 0.99 g of CuO@Viod@SiO2 support was dispersed in 50 mL of deionized water at 30 °C, and 1.04 mL of 58.56 mM HAuCl4 solution was added. After stirring at 30 °C for 4 h, 2 mg / mL of lilac leaf extract was added, and the stirring was continued for another 4 h. After the reaction was completed, the product was washed several times with deionized water. The filter cake was obtained by filtration, dried at 60 °C for 12 h, and finally calcined at 350 °C for 2 h under air atmosphere (heating rate of 2 °C / min) to obtain the final product Au / CuO@Viod@SiO2 catalyst.

[0052] Example 4

[0053] (1) Mechanical method for preparing CuO: CuCl2·2H2O, NaCO3, and NaCl were first dehydrated at 170 °C for 14 h. Then, 2 g of CuCl2, 2 g of Na2CO3, 12 g of NaCl, 0.4 g of SBA-15, and 243 g of zirconia grinding balls (mass ratio of grinding balls to material = 15:1) were ground in a zirconia jar. After 30 min, the solid powder was collected and calcined at 500 °C for 2 h with a heating rate of 5 °C / min in a muffle furnace. After washing with a large amount of deionized water, the filter cake was dried at 60 °C for 12 h. The obtained product was CuO.

[0054] (2) One-pot preparation of CuO@Viod@SiO2 carrier: 0.25 g of CuO was ultrasonically dispersed into 80 mL of water and 202.5 mL of anhydrous ethanol, 7.5 g of ammonia water and 0.7 g of RF precursor were sequentially added under continuous stirring, 0.54 g of CTAB and 1.17 g of TEOS were added under vigorous stirring after the reaction for 18 h, and the reaction was continued for 6 h, the reaction liquid was collected in a polytetrafluoroethylene liner in a stainless steel reaction kettle at 100 ℃ for 24 h, and then cooled to room temperature. Wash with a large amount of deionized water, dry the filter cake at 60 ℃ for 24 h, and finally calcine at 500 ℃ under air atmosphere for 5 h (the heating rate is 5 ℃ / min), and the CuO@Viod@SiO2 yolk-shell structure carrier is obtained after high-temperature carbonization.

[0055] (3) Preparation of Au / CuO@Viod@SiO2 catalyst by plant reduction method: 0.99 g of CuO@Viod@SiO2 carrier was dispersed in 50 mL of deionized water at 30 ℃, 1.04 mL of 58.56 mM HAuCl4 solution was added, and the reaction was stirred at 30 ℃ for 4 h, then 2 mg / mL of lilac leaf extract was added, and the stirring reaction was continued for 4 h. After the reaction was completed, wash several times with deionized water. The filter cake was obtained by filtration, dried at 60 ℃ for 12 h, and finally calcined at 350 ℃ under air atmosphere for 2 h (the heating rate is 2 ℃ / min), and the final product Au / CuO@Viod@SiO2 catalyst was obtained.

[0056] Example 5

[0057] The preparation conditions and process of the catalyst are consistent with those of Example 4, except that 2 mg / mL of lilac leaf extract is replaced by 2 mg / mL of peach leaf extract, and the final product Au / CuO@Viod@SiO2 catalyst is obtained.

[0058] The Au / CuO@Viod@SiO2 catalyst prepared in Examples 1, 2, 3 and 4 is subjected to TEM test, and the results are shown in FIG. 1. Figure 1 As shown in FIG. 1, it can be seen that:

[0059] 1. The change of the amount of TEOS doping will affect the size of the yolk-shell carrier of the final product Au / CuO@Viod@SiO2 catalyst. With the decrease of the amount of TEOS doping, the thickness of the SiO2 shell gradually thins, and when the amount of TEOS is 1.17 g, the shell thickness is 11.9 nm, and the catalytic performance is best.

[0060] 2. The reduction of the amount of CTAB doping will affect the morphology of the yolk-shell carrier of the final product Au / CuO@Viod@SiO2 catalyst, and the thickness of the SiO2 shell will be reduced to different degrees. When the amount of CTAB is 0.54 g, the shell thickness is 9.4 nm, and the catalytic performance is best.

[0061] 3. The change of RF resin layer will affect the interlayer void, and the catalyst particle size is 89.2 nm and the catalytic performance is best when RF is 0.7 g.

[0062] The Au / CuO@Viod@SiO2 catalysts prepared in Example 1, Example 2, Example 3, Example 4 and Example 5 were prepared according to the molar ratio of glycerol to gold of 100:1, 25 mL of 0.1M glycerol aqueous solution and 0.4927 g of Au / CuO@Viod@SiO2 catalyst were added to a batch high-pressure reaction kettle, and after complete sealing, nitrogen and oxygen were used to exhaust three times at room temperature, then 1.0 MPa of oxygen was filled, stirred and heated to 100℃, and constant temperature reaction was carried out for 2 h, after the reaction was completed, the reaction liquid was cooled to room temperature with an ice water mixture, filtered with a needle filter, and the conversion rate of glycerol and the selectivity of DHA were detected by high performance liquid chromatography, and the results are shown in Table 1.

[0063] Table 1. Test results of glycerol conversion rate and DHA selectivity of catalysts obtained in Examples 1-4.

[0064]

[0065] From Table 1 combined with Figure 1 It can be seen that the change of the doping amount of TEOS, CTAB and RF resin layer will cause the change of the morphology of the catalyst carrier, the shell thickness and the interlayer void, and then affect the catalytic activity of the catalyst. At the same time, the activity of the catalyst obtained under the same preparation conditions in Example 5 is significantly lower than that of the extract of Syringa oblata Lindl. This is because the concentration and proportion of the oxidation-reduction components contained in different plant extracts will affect the preparation of gold active components. The extract of Syringa oblata Lindl. selected in the present application has good reducing capacity and protection capacity for gold nanoparticles, and is a good green medium for preparing high-performance glycerol oxidation catalysts. In the present application, when TEOS = 1.17 g, CTAB = 0.54 g, RF = 0.7 g, and the plant matter is Syringa oblata Lindl., the catalyst performance is best, the glycerol conversion rate reaches 92.9%, and the DHA selectivity reaches 91.3%.

[0066] Catalytic oxidation of glycerol to prepare DHA was tested for cycle performance: the Au / CuO@Void@SiO2 catalyst obtained in Example 4 was filtered, washed, recovered, and reused according to the mass ratio of glycerol to gold. The washed catalyst and 25 mL of glycerol aqueous solution (0.1 mol / L) were added to the reaction kettle, which was purged with nitrogen and oxygen for 3 times, respectively, and then operated at 1 MPa of pure O2. The rotation speed of the reaction kettle was adjusted to 500 r / min, the reaction vessel was heated to 100℃ and the timing was started, and after 2 h of reaction, the high-pressure reactor was cooled to room temperature with an ice-water mixture, and the remaining gas in the reaction kettle was discharged. The test liquid was filtered with a needle filter, and the reaction liquid was detected by high performance liquid chromatography to determine the conversion rate of glycerol and the selectivity of DHA. The catalyst was filtered, washed, recovered and reused for five cycles, and the results of the cycle performance test are shown in Table 3, and the TEM images of the fresh catalyst and the catalyst after five cycles are shown in Figure 2

[0067] Table 3. Conversion rate of glycerol and DHA selectivity results of catalyst obtained in Example 4 after five cycles.

[0068]

[0069] As can be seen from Table 2, the conversion rate of glycerol and the selectivity of DHA of the catalyst prepared in Example 4 after five cycles are basically unchanged, both of which are stable at about 90%, and the catalyst has excellent stability.

[0070] As can be further seen from Figure 2 , the morphology and particle size of the catalyst before and after the cycle are basically unchanged, and no obvious structure collapse occurs, indicating that the catalyst has good structural stability and the structure is not destroyed in the glycerol reaction.

[0071] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents of the specification, and the technical scope must be determined according to the scope of the claims.​

Claims

1. A method for preparing a high-stability catalyst with a yolk-shell structure, characterized in that: The steps include: Step 1: dispersing copper oxide in a first solvent at room temperature to obtain a mixture A; Step 2: adding a precipitant and a layering resin to mixture A in a first stirring state at room temperature, and reacting for 16-20 hours to obtain mixture B; Step 3: Add a surfactant and a silicon source to mixture B under a second stirring state at room temperature, and react for 4-8 hours to obtain mixture C; Step 4: Separate the mixture C into solid and liquid, take the liquid phase, react at 100-120°C for 20-28h, and then cool to room temperature to obtain intermediate product D; Step 5: washing and drying the intermediate product D to obtain the intermediate product E; Step 6: calcining the intermediate product E at 450-550° C. in an air environment for 3-5 hours and cooling to room temperature to obtain the intermediate product F; Step 7: Disperse the intermediate product F in a second solvent at 25-35° C., add tetrachloroauric acid solution, and react at 25-35° C. under a third stirring state for 4-12 hours to obtain a mixture G; Step 8: Maintaining the reaction conditions of step 7 unchanged, add the extract of lilac leaves to the mixture G and react for 4-8 hours to obtain pre-product H; Step 9: washing and drying the pre-product H to obtain the pre-product I; Step 10: calcining the pre-product I at 300-400° C. for 1-3 hours in an air environment, and cooling to room temperature to obtain the yolk-shell structured high-stability catalyst.

2. The method for preparing the highly stable catalyst with yolk-shell structure according to claim 1, characterized in that: The copper oxide in step 1 is prepared by the following method: Step 101: Dehydrating copper chloride dihydrate, sodium carbonate, and sodium chloride at high temperature. Step 102: 1-3 parts of dehydrated copper chloride, 1-3 parts of sodium carbonate, 3-8 parts of sodium chloride, and 0.1-0.3 parts of SBA-15 are placed in a ball mill and ground to obtain a powdery product. Step 103: calcining the powdered product obtained in step 102 in an air environment at 450-550° C. for 1-3 hours to obtain a calcined product; during the calcination in step 103, the heating rate is 4-8° C. / min; In step 104, the calcined product obtained in step 103 is washed and dried to obtain the copper oxide.

3. The method for preparing the high-stability catalyst of the yolk-shell structure according to claim 1, characterized in that: Step 1: The first solvent is prepared by mixing deionized water and anhydrous ethanol in a ratio of deionized water to anhydrous ethanol of 1:2-3 (volume ratio).

4. The method for preparing the highly stable catalyst with yolk-shell structure according to claim 1, characterized in that: In step 1, the amount of the first solvent added is 100-1000 times the amount of copper oxide added; in step 2, the amount of the precipitant added is 25-35 times the amount of copper oxide added, and the amount of the layering resin added is 1.2-12 times the amount of copper oxide added; in step 3, the amount of the surfactant added is 1.2-6.8 times the amount of copper oxide added, and the amount of the silicon source added is 2-16 times the amount of copper oxide added.

5. The method for preparing the high-stability catalyst with yolk-shell structure according to claim 1, characterized in that: When the calcination is performed in step 6, the heating rate is 3-6°C / min; when the calcination is performed in step 10, the heating rate is 1-3°C / min.

6. The method for preparing the high-stability catalyst with yolk-shell structure according to claim 1, characterized in that: The stirring rate of the first stirring state is 100-300 r / min; the stirring rate of the second stirring state is 1000-3000 r / min; and the stirring rate of the third stirring state is 200-300 r / min.

7. The method for preparing the highly stable catalyst with yolk-shell structure according to claim 1, characterized in that: In step 7, the second solvent is deionized water, and the amount of the second solvent added is 45-55 times the amount of the intermediate product F added.

8. The method for preparing the highly stable catalyst with yolk-shell structure according to claim 1, characterized in that: The amount of tetrachloroauric acid added in step 7 is: 58-60 mM tetrachloroauric acid per 1 g of intermediate product F; the amount of plant leaf extract added in step 8 is: 1-3 mg / mL.

9. A high-stability catalyst with a yolk-shell structure, characterized in that: The catalyst is prepared by the preparation method of the high-stability catalyst with yolk-shell structure according to any one of claims 1 to 8, and has the structural formula: Au / CuO@Viod@SiO2.

10. Use of the high-stability catalyst with yolk-shell structure according to claim 9 in the catalytic oxidation of glycerol to produce 1,3-dihydroxyacetone.

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