CN115999533A - WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof - Google Patents
WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof Download PDFInfo
- Publication number
- CN115999533A CN115999533A CN202111226599.7A CN202111226599A CN115999533A CN 115999533 A CN115999533 A CN 115999533A CN 202111226599 A CN202111226599 A CN 202111226599A CN 115999533 A CN115999533 A CN 115999533A
- Authority
- CN
- China
- Prior art keywords
- catalyst
- zro
- sio
- solid acid
- acid catalyst
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses a WO 3 ‑SiO 2 ‑ZrO 2 Solid acid catalyst and preparation method thereof, WO in the catalyst 3 The loading of the catalyst is 5.0 to 15.0 weight percent, siO 2 The loading of the catalyst is 2.5 to 20.0 weight percent, and the balance is ZrO 2 . The preparation method comprises the following steps: mixing and dissolving a tungsten-containing compound and a zirconium-containing compound; adding silica sol, surfactant and precipitant to form gel, filtering, washing and roasting. The solid acid catalyst has strong interaction between active species and a carrier through gel adsorption, so that the recycling rate of the catalyst is improved; adopts a simple and easy precipitation methodThe raw materials are cheap and easy to obtain; the catalyst is easy to separate as a heterogeneous catalyst, can effectively reduce the residual amount of heavy metal tungsten in tartaric acid crystals, has higher DL-tartaric acid yield when being recycled, and reduces the production cost of tartaric acid; is suitable for mass production.
Description
Technical Field
The invention relates to an acid catalyst and a preparation method thereof, in particular to a WO 3 -SiO 2 -ZrO 2 A solid acid catalyst and a preparation method thereof.
Background
Tartaric acid (2, 3-dihydroxysuccinic acid) is a carboxylic acid and has wide application as an additive and a resolving agent in foods and medicines. Maleic anhydride is used as a raw material, hydrogen peroxide is used as an oxidant, tungstic acid is used as a catalyst, epoxy succinic acid is generated by catalytic oxidation, tartaric acid is obtained by hydrolysis, and DL-tartaric acid is obtained by cooling, crystallization, separation and drying. Although the tungstic acid catalyst can obtain higher tartaric acid yield, the tungstic acid catalyst has the defect of difficult separation as a homogeneous catalyst, and easily causes the exceeding of the heavy metal content in tartaric acid products.
The heterogeneous catalyst for preparing tartaric acid by maleic anhydride or maleic acid catalytic oxidation at present is mainly supported on different carriers and adopts WO 3 A catalyst which is an active component.
Patent CN1381436 discloses a hydrothermal synthesis method of WO 3 -MCM-41 catalyst for the preparation of tartaric acid from maleic acid, the yield of tartaric acid after one cycle being reduced by 13%; hao Jia (Fine chemical engineering, 2016, 33:440-444) the PW/SiO is prepared by loading tungsten-phosphorus onto silicon spheres by impregnation method 2 Catalyst for preparing tartaric acid from maleic acid and circulating onceThe yield of post-tartaric acid was reduced by 33%. The yield of tartaric acid is reduced due to the relatively weak forces between the active species and the carrier, resulting in a greater amount of the active component WO during the reaction 3 And phosphorus is dissolved into the reaction liquid, so that the tartaric acid crystallization product finally contains more tungsten and phosphorus. In addition, hydrothermal process for preparing WO 3 The MCM-41 catalyst has long synthesis period and needs high-temperature and high-pressure operation links, and the method has higher requirements on production equipment and is not easy to realize large-scale production. PW/SiO 2 And WO 3 /TiO 2 In the preparation process of the catalyst, the preparation of the carrier is required to be carried out after the impregnation of the carrier 3 The production period is long and the process is relatively complex.
Thus, the prior art regarding heterogeneous catalysts has mainly the following drawbacks: the preparation process is complex, the production period is long, the catalyst cannot be recycled, and the catalyst is easy to use, so that the production cost of tartaric acid is increased.
Disclosure of Invention
The invention aims to: the invention aims to provide a WO with strong binding force between active substances and carriers and easy recycling 3 -SiO 2 -ZrO 2 A solid acid catalyst;
another object of the present invention is to provide a WO with readily available raw materials, simple process and easy recycling 3 -SiO 2 -ZrO 2 A method for preparing a solid acid catalyst.
The technical scheme is as follows: WO according to the invention 3 -SiO 2 -ZrO 2 Solid acid catalyst, said WO 3 -SiO 2 -ZrO 2 WO in solid acid catalysts 3 The loading of the catalyst is 5.0 to 15.0 weight percent, siO 2 The loading of the catalyst is 2.5 to 20.0 weight percent, and the balance is ZrO 2 。
Among them, WO is preferred 3 The loading of the catalyst is 7.5 to 15.0 weight percent, siO 2 The loading of (2.5-10.0 wt.%) and the balance ZrO 2 。
Wherein said WO 3 -SiO 2 -ZrO 2 The solid acid catalyst is synthesized in one step by a precipitation method. Said WO 3 -SiO 2 -ZrO 2 Solid acid catalystComprises a tungsten-containing compound, a silicon-containing compound and a zirconium-containing compound, wherein the tungsten-containing compound is adsorbed on a gel of silicon hydroxide and zirconium hydroxide.
WO as described above 3 -SiO 2 -ZrO 2 A method for preparing a solid acid catalyst comprising the steps of:
(1) Mixing and dissolving a tungsten-containing compound and a zirconium-containing compound;
(2) Adding silica sol, surfactant and precipitant to form gel, filtering, washing and roasting.
Wherein the tungsten-containing compound is at least one of ammonium metatungstate, ammonium tungstate, sodium tungstate or phosphotungstic acid; the zirconium-containing compound is at least one of zirconium oxychloride, zirconium nitrate or zirconium sulfate. Wherein the silica sol is preferably an acidic silica sol.
Wherein the precipitant is one of ammonia water, naOH, KOH or urea; the concentration of the precipitant solution is 1.0-12.0 mol/L; preferably 1.0 to 6.0mol/L; the pH value of the system is 7-14 after adding the precipitant.
Wherein the concentration of the zirconium-containing compound solution is 0.1 to 2.0mol/L, preferably 0.1 to 0.5mol/L.
Wherein the surfactant is at least one of polyethylene glycol, polyvinyl alcohol, tween-80, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and fluorine-containing anionic surfactant.
Wherein the dosage of the surfactant is WO 3 -SiO 2 -ZrO 2 ZrO in solid acid catalyst 2 5-20wt% of the weight; preferably 10 to 20% by weight.
Wherein the roasting temperature is 350-700 ℃ and the roasting time is 1-10 h; preferably at 400-550 deg.c for 2-6 hr.
Basic principle: the invention fully adopts the principle that the positive charges on the periphery of the precipitator gel can effectively adsorb anions, and as shown in figure 1, the WO is prepared by a precipitation method 3 -SiO 2 -ZrO 2 In the process of the catalyst, when the alkaline solution is dripped into the salt solution, si (OH) is generated x And Zr (OH)) x The seed crystal can absorb the tungsten-containing anionic compound immediately, so that the tungsten-containing anionic compound is uniformly distributed on the surface of the gel, and the absorbed anionic compound can play a role in inhibiting Si (OH) by steric hindrance x And Zr (OH) x Seed crystal growth, which promotes the generation of W-O-Zr bond and increases the specific surface area of the catalyst during calcination, resulting in WO x The species are more uniformly dispersed on the surface of the catalyst, the interaction force between the carriers is stronger, and more Lewis acid can be provided.
Due to WO 3 -SiO 2 -ZrO 2 WO in the catalyst x The Lewis acid sites provided by the (W-OH and W-O-Zr) species are capable of forming a tungsten-containing peroxy compound with hydrogen peroxide, which combines with maleic acid to form maleic acid-tungsten-containing peroxy compound, which undergoes proton transfer to form epoxysuccinic acid and water, as shown in FIG. 2. Under the high temperature and acidic conditions, the oxygen in the tricyclic ether structure in the epoxy succinic acid is first protonated, so that the polarity of hydrocarbon bonds is enhanced, and water is used as a nucleophile to react with carbon in the tricyclic ether structure to generate DL-tartaric acid. The invention adopts a simple and easy precipitation method to prepare the WO 3 -SiO 2 -ZrO 2 Solid acid catalyst for the preparation of tartaric acid from maleic anhydride, easy to separate as heterogeneous catalyst and active species WO 3 With SiO 2 -ZrO 2 The strong interaction exists between the composite oxides, so that the catalyst can be recycled, and the catalyst still has higher DL-tartaric acid yield and higher tartaric acid crude product with higher purity during recycling, thereby reducing the production cost of tartaric acid and having important application significance.
The beneficial effects are that: compared with the prior art, the invention has the following remarkable effects: 1. the solid acid catalyst has strong interaction between active species and a carrier through gel adsorption, so that the recycling rate of the catalyst is improved; 2. the solid acid catalyst is synthesized in one step by adopting a simple and feasible precipitation method, and the raw materials are cheap and easy to obtain; 3. the catalyst is easy to separate as a heterogeneous catalyst, can effectively reduce the residual amount of heavy metal tungsten in tartaric acid crystals, has higher DL-tartaric acid yield when being recycled, and reduces the production cost of tartaric acid; 4. is suitable for mass production.
Drawings
FIG. 1 is a diagram of a catalyst synthesis mechanism according to the present invention;
FIG. 2 is a diagram of a reaction mechanism for preparing epoxysuccinic acid by the catalyst of the present invention;
FIG. 3 is a NH based on the catalyst of example 3 of the present invention 3 -DRTFIR profile;
FIG. 4 is an XRD pattern for the catalyst of example 4 of the invention;
FIG. 5 is a BET spectrum of the catalyst of example 4 of the present invention;
FIG. 6 is a schematic representation of crude tartaric acid according to example 5 of the present invention;
FIG. 7 is an HPLC chart of crude tartaric acid of example 5 of the present invention;
FIG. 8 is an XRD pattern for the catalyst of example 10 of the present invention after activation 5 times;
FIG. 9 is a graph showing the sum IR spectrum of the catalyst of example 10 of the present invention after 5 times of activation.
Detailed Description
The invention is described in further detail below with reference to the drawings.
Example 1
7.5% WO 3 -5％SiO 2 -ZrO 2 The preparation method of the solid acid catalyst comprises the following steps of
(1) Under the conditions of 25 ℃ and 600r/min stirring speed, respectively weighing 3.0g of ammonium metatungstate and 52.2g of zirconium oxychloride, dissolving into 630ml of deionized water, heating to 100 ℃, continuously stirring for 2 hours, and cooling to room temperature;
(2) Respectively adding 5.7g of acidic silica sol and 2.0g of polyethylene glycol into the solution, stirring for 30min until the solution is fully mixed, dropwise adding 2mol/L ammonia water solution into the solution until the pH value is=9.0 in 40min, continuously stirring, performing suction filtration, washing with deionized water until no chloride ions are detected in the filtrate by using 1mol/L silver nitrate water solution, taking out a filter cake, putting the filter cake into 200ml of absolute ethyl alcohol, pulping for 15min, performing suction filtration again, re-washing the filter cake by using 500ml of absolute ethyl alcohol, and performing suction filtration on the filter cake at 500 DEG CRoasting for 4 hours to obtain 7.5% WO 3 -5％SiO 2 -ZrO 2 A solid acid catalyst.
Example 2
10% WO 3 -5％SiO 2 -ZrO 2 A method for preparing a solid acid catalyst comprising the steps of:
(1) 2.42g of ammonium tungstate and 57.6g of zirconium sulfate are respectively dissolved in 330ml of deionized water under the conditions of the temperature of 25 ℃ and the stirring speed of 600r/min, the temperature is raised to 100 ℃, stirring is continued for 2 hours, and the mixture is cooled to room temperature;
(2) Respectively adding 5.7g of acidic silica sol and 4.0g of Tween-80 into the solution, stirring for 30min until the solution is fully and uniformly mixed, dropwise adding 1mol/L of sodium hydroxide aqueous solution into the solution until the pH value is=8.2 within 40min, continuously stirring, performing suction filtration, flushing a filter cake by taking deionized water as a detergent until the conductivity of filtrate is consistent with that of the detergent, taking out the filter cake, putting the filter cake into 200ml of absolute ethyl alcohol, pulping for 15min, re-suction filtering the filter cake, re-washing the filter cake by 500ml of absolute ethyl alcohol, and roasting the filter cake at 550 ℃ for 3h to obtain 10% WO 3 -5％SiO 2 -ZrO 2 A solid acid catalyst.
Example 3
7.5% WO 3 -2.5％SiO 2 -ZrO 2 A method for preparing a solid acid catalyst comprising the steps of:
(1) 2.31g of sodium tungstate and 69.5g of zirconium nitrate are weighed and respectively dissolved into 1620ml of deionized water under the conditions of 25 ℃ and stirring speed of 600r/min, the temperature is raised to 100 ℃, stirring is continued for 2 hours, and cooling is carried out to room temperature;
(2) Respectively adding 2.8g of acidic silica sol and 3.0g of polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer into the solution, stirring for 30min until the solution is fully mixed, dropwise adding 4mol/L potassium hydroxide solution into the solution until the pH value is 7 within 40min, continuously stirring, performing suction filtration, flushing the solution with 1wt% ammonium acetate solution as a detergent until the conductivity of the filtrate is consistent with that of the detergent, taking out a filter cake, pulping the filter cake in 200ml of absolute ethyl alcohol for 15min, performing suction filtration again, and then weighing the filter cake with 500ml of absolute ethyl alcoholNew washing, roasting the filter cake at 400 deg.C for 6h to obtain 7.5% WO 3 -2.5％SiO 2 -ZrO 2 Solid acid catalyst, NH of the catalyst 3 The DRTFIR spectrum is shown in FIG. 3, and it can be seen from FIG. 3 that the catalyst has a large number of Brownian acidic centers and a large number of Lewis acidic centers, and the acidic centers are favorable for the catalytic reaction.
Example 4
15% WO 3 -10％SiO 2 -ZrO 2 A method for preparing a solid acid catalyst comprising the steps of:
(1) Under the conditions of 25 ℃ and 600r/min stirring speed, weighing 3.11g of phosphotungstic acid and 37.3 g of zirconium oxychloride, respectively dissolving into 1000ml of deionized water, heating to 100 ℃, continuously stirring for 2 hours, and cooling to room temperature;
(2) Respectively adding 11.2g of acidic silica sol and 3.0g of laureth into the solution, stirring for 30min until the solution is fully and uniformly mixed, dropwise adding 6mol/L urea solution into the solution until the pH value is=12 within 40min, continuously stirring, performing suction filtration, flushing with deionized water as a detergent until the conductivity of the filtrate is consistent with that of the detergent, taking out a filter cake, pulping in 200ml of absolute ethyl alcohol for 15min, re-suction filtering, re-washing the filter cake with 500ml of absolute ethyl alcohol, and roasting the filter cake at 480 ℃ for 2h to obtain 15% WO 3 -10％SiO 2 -ZrO 2 A solid acid catalyst.
The XRD pattern of the catalyst is shown in FIG. 4, and it can be seen that the catalyst only has tetragonal zirconia crystal form, and SiO is not seen 2 And WO 3 The corresponding diffraction peaks of the crystalline phases indicate that the catalyst is uniformly dispersed on the surface of the catalyst. The BET spectrum of the catalyst is shown in FIG. 5, and it can be seen that the catalyst has large specific surface area and regular pore channels.
Example 5
25.0g of maleic anhydride was weighed into 60.0g of deionized water, heated to 50℃until it was sufficiently dissolved, 1.3g of the catalyst obtained in example 1 was added thereto, which catalyst accounted for 5.2% by weight of maleic anhydride, and then 58.0g of 30% by weight of H was added in 6 minutes 2 O 2 Adding the solution into the reaction kettle, heating the reaction solution to 65 ℃ for epoxidation reaction for 6 hours, separating and collecting the catalyst by a filtering mode, heating the reaction solution again to 95 ℃ for hydrolysis for 6 hours, concentrating the reaction solution to half of the volume of the original solution at 95 ℃, cooling and crystallizing the reaction solution at 3 ℃, filtering, washing and drying the reaction solution to obtain a DL-tartaric acid crude product. The conversion of maleic anhydride in the epoxidation reaction was 59.6% and the actual tartaric acid yield after the final reaction was 42.3%. Although the conversion of fresh catalyst is reduced compared to the prior art, the higher conversion in the prior art is due to WO 3 The leaching is caused by the participation of a homogeneous catalyst in the reaction, and the problems that metal components are easy to remain and the catalyst cannot be recycled exist in the situation. Therefore, although the tartaric acid yield finally obtained in this example was 42.3%, the catalyst was recyclable and there was no problem of metal component residue.
The HPLC spectrum of the crude tartaric acid prepared in the embodiment is shown in a schematic diagram 6, and is shown in fig. 7, and the sample is white DL-tartaric acid crude with purity of 98% can be seen from fig. 6 and 7, which shows that the method can synthesize the crude tartaric acid with less impurities and high purity.
Example 6
20.8g of maleic anhydride was weighed into 60.0g of deionized water, heated to 50℃until it was sufficiently dissolved, 2.1g of the catalyst obtained in example 2, which was 10.0% by weight based on the mass of maleic anhydride, was added thereto, and then 76.0g of 30% by weight of H was added in 6 minutes 2 O 2 Adding the solution into the solution, heating the solution to 70 ℃ for epoxidation reaction for 4 hours, separating and collecting the catalyst by a simple filtering mode, heating the solution to 90 ℃ again for hydrolysis for 8 hours, concentrating the solution to half of the volume of the original solution at 100 ℃, cooling and crystallizing at 6 ℃, filtering, washing and drying to obtain DL-tartaric acid. The conversion of maleic anhydride in the epoxidation reaction was 88.3%, and the actual tartaric acid yield after the final reaction was 73.2%.
Example 7
24.0g maleic anhydride is weighed and dissolved in 60.0g deionized water, the temperature is raised to 50 ℃ until the maleic anhydride is fully dissolved,3.6g of the catalyst obtained in example 3, which represents 15.0% by weight of maleic anhydride, was added thereto, and then 50.0g of 30% by weight of H was added in 6 minutes 2 O 2 Adding the solution into the solution, heating the solution to 72 ℃ for epoxidation reaction for 5 hours, separating and collecting the catalyst by a simple filtering method, heating the solution again to 95 ℃ for hydrolysis for 6 hours, concentrating the solution to half of the volume of the original solution at 90 ℃, cooling and crystallizing the solution at 9 ℃, filtering, washing and drying the solution to obtain DL-tartaric acid. The conversion of maleic anhydride in the epoxidation reaction was 65.1%, and the actual tartaric acid yield after the final reaction was 48.1%. The reasons for the reduced conversion of this catalyst compared to the fresh catalyst of the prior art are described in example 5.
Example 8
26.5g of maleic anhydride was weighed out in 60.0g of deionized water, heated to 50℃until it was sufficiently dissolved, 5.3g of the catalyst obtained in example 4 was added thereto, which catalyst made up of 20.0% by weight of maleic anhydride, and 122g of 30% by weight of H was then added in 6 minutes 2 O 2 Adding the catalyst into the reaction solution, heating the reaction solution to 75 ℃ for epoxidation reaction for 3 hours, separating and collecting the catalyst by a simple filtering mode, heating the reaction solution to 90 ℃ again for hydrolysis for 10 hours, concentrating the reaction solution to half of the volume of the original solution at 95 ℃, and cooling and crystallizing at 5 ℃. The conversion of maleic anhydride in the epoxidation reaction was 96.1%, and the actual tartaric acid yield after the final reaction was 81.4%.
Example 9
20.8g of maleic anhydride was weighed into 60.0g of deionized water, heated to 50℃until it was sufficiently dissolved, 2.1g of the catalyst obtained in example 1 was added thereto, which catalyst accounted for 10.0% by weight of maleic anhydride, and 53.0g of 30% by weight of H was then added in 6 minutes 2 O 2 Adding the solution into the solution, heating the solution to 70 ℃ for epoxidation reaction for 4 hours, separating and collecting the catalyst by a simple filtering method, heating the solution to 90 ℃ again for hydrolysis for 8 hours, concentrating the solution to half of the volume of the original solution at 80 ℃, cooling and crystallizing at 6 ℃, filtering, washing and drying to obtain DL-tartaric acid. Washing the collected catalystWashing, drying and activating for 12 hours at 300 ℃ for the next reaction. As shown in tables 1 and 2, the catalyst recycling performance was examined, and the reaction was carried out 5 times in a total cycle.
TABLE 1 7.5% WO 3 -5％SiO 2 -ZrO 2 Catalyst circulation reaction
| Number of reactions | Maleic anhydride conversion (%) | Yield of DL-tartaric acid (%) |
| 1 | 68.2 | 51.2 |
| 2 | 66.9 | 49.1 |
| 3 | 64.9 | 49.8 |
| 4 | 65.6 | 46.7 |
| 5 | 61.8 | 47.1 |
TABLE 2 7.5% WO 3 -5％SiO 2 -ZrO 2 Analysis of elemental content before and after catalyst reaction (XRF)
| Catalyst | WO 3 (wt％) | SiO 2 (wt％) |
| 7.5％WO 3 -5％SiO 2 -ZrO 2 (before reaction) | 7.72 | 4.96 |
| 7.5％WO 3 -5％SiO 2 -ZrO 2 (after the reaction) | 7.56 | 4.77 |
As can be seen from tables 1 and 2, 7.5% WO 3 -5％SiO 2 -ZrO 2 The conversion and the actual yield after 5 times of recycling of the catalyst are reduced by only 6.4% and 4.1%, and WO x Species and SiO x The loss of the species is small, which shows that the catalyst has better cyclic reaction performance of preparing DL-tartaric acid by epoxidation of maleic anhydride, the activity of the catalyst is more stable after 5 times of reaction, and the catalyst still has higher yield of DL-tartaric acid.
Example 10
20.8g of maleic anhydride was weighed into 60.0g of deionized water, heated to 50℃until it was sufficiently dissolved, 2.1g of the catalyst obtained in example 2, which was 10.0% by weight based on the mass of maleic anhydride, was added thereto, and then 76.0g of 30% by weight of H was added in 6 minutes 2 O 2 Putting the mixture into the reactor, and heating the reaction solution to 70 DEG CAnd (3) epoxidation reaction is carried out for 4 hours, a catalyst is separated and collected through a simple filtering mode, the reaction liquid is heated to 100 ℃ again to hydrolyze for 8 hours, then concentrated to half of the volume of the original solution at 80 ℃, cooled to crystallize at 6 ℃, filtered, washed and dried to obtain DL-tartaric acid. The collected catalyst was washed, dried, and activated at 600 c for 1 hour for the next reaction, and as shown in table 3, the catalyst recycling performance was examined, and the reaction was co-circulated for 5 times.
The XRD patterns and IR spectra of the catalyst after 5 activations are shown in FIGS. 8 and 9, respectively. As can be seen from FIG. 8, only tetragonal zirconia diffraction peaks are present on the catalyst, no SiO is seen 2 And WO 3 The diffraction peaks of (2) indicate that the active species remain highly dispersed on the catalytic surface, and it can be seen from FIG. 9 that only ZrO is present on the activated catalyst 2 The corresponding infrared vibratory peak was not seen with respect to maleic acid, epoxysuccinic acid or DL-tartaric acid.
TABLE 3 10% WO 3 -5％SiO 2 -ZrO 2 Catalyst circulation reaction
| Number of reactions | Maleic anhydride conversion (%) | Yield of DL-tartaric acid (%) |
| 1 | 88.1 | 73.4 |
| 2 | 85.6 | 70.5 |
| 3 | 83.4 | 68.1 |
| 4 | 82.1 | 67.1 |
| 5 | 80.3 | 65.3 |
As can be seen from FIGS. 8, 9 and Table 3, 10% WO after activation 3 -5％SiO 2 -ZrO 2 The structure and the dispersion state of the active components of the catalyst are not changed, no organic matter covers the surface of the catalyst, and the conversion rate and the actual yield are only reduced by 7.8 percent and 8.1 percent after the catalyst is recycled for 5 times, which shows that the catalyst has better cyclic reaction performance for preparing DL-tartaric acid by epoxidation of maleic anhydride after simple high-temperature activation, and the catalyst activity is relatively stable after 5 times of reaction, and still has higher DL-tartaric acid yield.
Claims (10)
1. WO (WO) 3 -SiO 2 -ZrO 2 A solid acid catalyst characterized in that the WO 3 -SiO 2 -ZrO 2 WO in solid acid catalysts 3 The loading of the catalyst is 5.0 to 15.0 weight percent, siO 2 The loading of the catalyst is 2.5 to 20.0 weight percent, and the balance is ZrO 2 。
2. WO according to claim 1 3 -SiO 2 -ZrO 2 A solid acid catalyst characterized in that the WO 3 -SiO 2 -ZrO 2 The solid acid catalyst is synthesized in one step by a precipitation method.
3. WO according to claim 1 3 -SiO 2 -ZrO 2 A solid acid catalyst characterized in that the WO 3 -SiO 2 -ZrO 2 The raw materials of the solid acid catalyst comprise a tungsten-containing compound, a silicon-containing compound and a zirconium-containing compound, wherein the tungsten-containing compound is adsorbed on silicon hydroxide and zirconium hydroxide gel.
4. WO (WO) 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized by comprising the following steps:
(1) Mixing and dissolving a tungsten-containing compound and a zirconium-containing compound;
(2) Adding silica sol, surfactant and precipitant to form gel, filtering, washing and roasting.
5. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized in that the precipitant is one of ammonia water, naOH, KOH or urea.
6. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 A process for preparing a solid acid catalyst characterized in that the surfactant is used in an amount of WO 3 -SiO 2 -ZrO 2 ZrO in solid acid catalyst 2 5-20wt% of the weight.
7. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized in that the surfactant is at least one of polyethylene glycol, polyvinyl alcohol, tween-80, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and fluorine-containing anionic surfactant.
8. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized in that the tungsten-containing compound is at least one of ammonium metatungstate, ammonium tungstate, sodium tungstate or phosphotungstic acid.
9. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized in that the zirconium-containing compound is at least one of zirconium oxychloride, zirconium nitrate or zirconium sulfate.
10. The process according to claim 4, wherein the process comprises 3 -SiO 2 -ZrO 2 The preparation method of the solid acid catalyst is characterized in that the roasting temperature is 350-700 ℃ and the roasting time is 1-10 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111226599.7A CN115999533A (en) | 2021-10-21 | 2021-10-21 | WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111226599.7A CN115999533A (en) | 2021-10-21 | 2021-10-21 | WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115999533A true CN115999533A (en) | 2023-04-25 |
Family
ID=86019733
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111226599.7A Pending CN115999533A (en) | 2021-10-21 | 2021-10-21 | WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115999533A (en) |
-
2021
- 2021-10-21 CN CN202111226599.7A patent/CN115999533A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1035320C (en) | Process for producing hydrogen peroxide | |
| KR101773694B1 (en) | Titanium stannate silicate, method of preparation and use thereof | |
| CN104495867B (en) | The preparation method of big particle diameter HTS | |
| JPH0529372B2 (en) | ||
| CN111036290A (en) | Preparation method of titanium silicalite molecular sieve for inhibiting byproduct generation in propylene epoxidation process | |
| CN111569876A (en) | Hydrogenation catalyst, preparation method and application thereof | |
| CN111017946B (en) | Preparation method of titanium-containing molecular sieve for olefin epoxidation process | |
| CN111330582A (en) | Preparation method and application of copper-based catalyst | |
| CN106082261A (en) | A kind of Ti MWW molecular sieve and preparation method thereof | |
| CN1173961C (en) | Catalyst for olefine epoxidation | |
| KR20100041000A (en) | The metal oxide catalyst for etherification reaction, the method thereof and the process for the production of linear polyglycerol using it | |
| CN111151238B (en) | Bismuth vanadate heterojunction BiVO4/Bi25VO40Material, preparation method and application thereof | |
| CN115999533A (en) | WO (WO) 3 -SiO 2 -ZrO 2 Solid acid catalyst and preparation method thereof | |
| JP2015134324A (en) | Copper-supported catalyst and method of producing the same, method of producing lactic acid, and method of producing formic acid | |
| CN116003249A (en) | Preparation method of DL-tartaric acid | |
| JP7376054B2 (en) | Method for producing a catalyst for dehydration reaction of 3-hydroxypropionic acid, catalyst for dehydration reaction of 3-hydroxypropionic acid, and method for producing acrylic acid using the same | |
| JPH05200299A (en) | Monoalkylene glycol catalyst having high selectivity | |
| CN104512906B (en) | Titanium-silicon molecular sieve and preparation method thereof | |
| CN106268972B (en) | A kind of preparation method of copper zinc-base hydrogenation catalyst | |
| CN108793183B (en) | Method for separating mother liquor of titanium-silicon molecular sieve | |
| SK29898A3 (en) | Catalyst mixture based on amorphous partially dehydrated zirconnium hydroxide and process for its manufacture and use thereof | |
| CN118287134A (en) | Modified titanium-silicon molecular sieve catalyst, preparation method and application thereof in preparation of epichlorohydrin | |
| CN117229248B (en) | Method for preparing and purifying vitronectin by using solid alkali | |
| CN1182033C (en) | Method for preparing niobium-silicon molecular sieve | |
| CN101304965A (en) | Process for producing carnitinamide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |