CN110040744B - MeAPSO-34 molecular sieve and preparation method thereof - Google Patents
MeAPSO-34 molecular sieve and preparation method thereof Download PDFInfo
- Publication number
- CN110040744B CN110040744B CN201910275358.8A CN201910275358A CN110040744B CN 110040744 B CN110040744 B CN 110040744B CN 201910275358 A CN201910275358 A CN 201910275358A CN 110040744 B CN110040744 B CN 110040744B
- Authority
- CN
- China
- Prior art keywords
- molecular sieve
- meapso
- bauxite
- hours
- crystallization
- 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.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
- C01B39/54—Phosphates, e.g. APO or SAPO compounds
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
- C01P2002/85—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by XPS, EDX or EDAX data
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
The invention provides a preparation method of a MeAPSO-34 molecular sieve, which comprises the following steps: the natural bauxite comprises the components of silicon element, iron element and titanium element. The technical scheme takes cheap and easily-obtained natural bauxite as a raw material, effectively utilizes resources such as aluminum, silicon, iron, titanium and the like in the natural bauxite, and prepares the bauxite into the composite hierarchical pore with micropore-mesopore and the like and the specific surface area of 250-653m by one step through a solid phase method2(ii) MeAPSO-34 molecular sieves (Me ═ Fe, Ti) per g.
Description
Technical Field
The invention relates to the field of mineral resource processing, in particular to a MeAPSO-34 molecular sieve and a preparation method thereof.
Background
The SAPO-34 molecular sieve has the same CHA topological structure as natural mineral chabazite, a special eight-membered ring structure and proper acidity of the molecular sieve, so that the SAPO-34 molecular sieve has extremely high selectivity of ethylene and propylene in MTO catalytic reaction. The molecular sieve which embeds metal atoms into SAPO-34 and is named MeAPSO-34 can show new structure and performance. The pore opening and the self-acidity of the molecular sieve change due to the entry of metal ions. The orifice is reduced, and the diffusion of macromolecules can be inhibited, so that the reaction is carried out towards a way favorable for the generation of micromolecular olefin; the Kang et al study showed the effect of SAPO-34 molecular sieves of different metal element types on the catalytic performance under MTO process conditions. The MTO catalytic reaction is as follows: the online time is 1h, the reaction is maintained at 450 ℃, and the selectivity of ethylene is compared, and the result is that: NiAPSO-34 is more than CoAPSO-34 and FeAPSO-34 is more than SAPO-34. Lei Xu et al found that the life comparison of SAPO-34 catalysts of different metal types to SAPO-34 catalysts in the MTO reaction resulted in: FeAPSO-34 is more than TiAPSO-34 and more than SAPO-34. Ho-Jeong Chaea et al report that the proton morphology of the nano-sized TiAPSO-34 molecular sieve obviously improves the selectivity of ethylene and propylene and relatively improves the catalytic stability in the MTO reaction. Zhang et al mixes metal Mg into SAPO-34 in different concentrations to prepare MgAPSO-34, and applies SAPO-34 and MgAPSO-34 in the reaction of preparing small molecular olefin by chloromethylation, and most experiments show that the addition of Mg inhibits the occurrence of hydrogen transfer reaction and has favorable influence on the activity of the catalyst. Sedighi et al found that metal atoms have a great influence on the structure and acidity of a molecular sieve by synthesizing MeAPSO-34(Me ═ Fe, Co, Ni, La, Ce) and comparing the MTO reaction performance thereof, and the introduction of the metal atoms increases the conversion rate of methanol, prolongs the service life of the catalyst, and improves the stability. The Fe-APSO-34 molecular sieve denitration catalyst for purifying NOx in tail gas of diesel vehicles is prepared by using an in-situ hydrothermal synthesis method for the poplar rain and the like, and has better NO conversion rate (more than 90 percent) in a high-temperature section (350-.
The synthesis of the MeAPSO-34 molecular sieve has two modes of embedding metal elements: (1) the method is a one-step synthesis method, namely, metal salts can be directly added in pure chemical raw materials or natural minerals rich in aluminum silicon, such as metal impurity components carried by bauxite, are crystallized to obtain MeAPSO-34 when a crystallized mixture is prepared; (2) is a stepwise synthesis method. Firstly, synthesizing the SAPO-34 molecular sieve, and then embedding the metal elements in the SAPO-34 molecular sieve by an ion exchange mode. Most of the MeAPSO-34 molecular sieves are usually prepared by a one-step synthesis method, and the process is simple and quick. However, if the method adopts pure chemical raw materials and metal nitrates are directly added, the cost is increased, and environmental pollution is easily caused in the crystallization or roasting process of the molecular sieve, such as waste liquid or release some toxic gases, such as nitric oxide and the like; compared with pure chemical raw materials and synthesis by directly adding metal nitrates, the method takes natural minerals rich in aluminum silicon as raw materials, has extremely low cost, can realize full conversion of mineral components including metal impurity components, is one of effective ways for high-valued minerals, and has great economic and social benefits. For example, the heteroatom aluminum phosphate molecular sieve MeSAPO-5, -11, -34, -44(Me ═ Fe, Ti) is synthesized by taking bauxite from Zhangpu county co-foaming bauxite limited company as a raw material by a hydrothermal method reported by Chenjingjing and the like; and the catalytic performance of the catalyst on the preparation of HMF by fructose dehydration is examined. However, the molecular sieve needs to be added with a certain amount of mineralizer HF with high toxicity in the synthesis process, and the development of a green process route is not met.
The specific synthesis method of the MeAPSO-34 molecular sieve is similar to that of the SAPO-34 molecular sieve, and comprises a traditional hydrothermal synthesis method, a solvothermal method, a microwave radiation crystallization method, gas phase transfer, ionic liquid heat and the like. In the traditional hydrothermal crystallization method, the reaction mixture is in a liquid state, and because the thermodynamic limit exists in the reaction of the liquid phase mixture, the raw materials cannot be completely converted, so that the yield is low. In the traditional process, the molecular sieve mother liquor is recycled, so that the process is complex, the product quality is difficult to ensure, and a large amount of sewage generated in the synthesis process can cause environmental pollution; the gas phase transfer method has too long initial gel preparation time.
Disclosure of Invention
Therefore, a new method for providing a MeAPSO-34(Me ═ Fe, Ti) molecular sieve with high raw material utilization rate, safety, environmental protection, economy and high efficiency is needed. In order to achieve the above object, the inventors provide a preparation method of a MeAPSO-34 molecular sieve, comprising the steps of:
pretreatment: removing impurities from natural bauxite, ball-milling and roasting to obtain pretreated bauxite;
acid treatment: carrying out acid treatment on the pretreated bauxite by using oxalic acid to obtain an activated bauxite mixture;
solid-phase synthesis: mixing the activated alumina mixture with deionized water, stirring, and sequentially adding phosphorus source (P) while stirring2O5) Supplementing silicon Source (SiO)2) Mixing the template agent and the mixture, and uniformly stirring to obtain a paste; the templating agent comprises TEA and TEAOH;
and (3) crystallization: crystallizing the paste at 140-220 ℃ until MeAPSO-34 crystals are formed, and centrifugally washing the crystallized material until the pH value of a washing liquid is 6.3-6.5 to obtain a precipitate;
and (3) post-treatment: drying and calcining the precipitate to obtain a MeAPSO-34 molecular sieve;
the natural bauxite contains aluminum element, silicon element, iron element and titanium element.
Further, the activated alumina mixture comprises the following active substances in percentage by mass:
Al2O3：68-85％；SiO2：8-13％；Fe2O3：2-18％；TiO2：1.5-2.0％。
further, the step of acid treatment also comprises drying and calcining the bauxite after the acid treatment to obtain an activated bauxite mixture; wherein the drying temperature is 110 ℃, and the calcining temperature is 550 ℃.
Further, the solid phase synthesis step is to synthesize Al in the material2O3：P2O5：SiO2：TEA：TEAOH：H2The molar ratio of O is 90-110: 90-110: 44-61: 258-261: 29-40: 2365-3258.
Further, PEG20000 and Al are added in the solid phase synthesis step2O3The molar ratio of PEG20000 is 9000-11000: 15-20.
Further, in the pretreatment step, the ball milling is carried out for 2 hours in a ball mill with the rotation speed of 500 revolutions, and the roasting is carried out for 4 hours in a muffle furnace at the temperature of 550 ℃.
Further, in the acid treatment step, the pretreated bauxite, oxalic acid and deionized water are mixed, and acid treatment is carried out for 3 hours at 95 ℃, wherein the mass ratio of the pretreated bauxite, the oxalic acid and the deionized water is 24-26: 43-48: 230-280.
Further, in the crystallization step, the crystallization time is 2-72 h.
Further, the post-treatment step is to dry the precipitate in an oven at 110 ℃ for 2h and calcine the precipitate in a muffle at 550 ℃ for 6h under an air atmosphere.
The inventor also provides a MeAPSO-34 molecular sieve, wherein the MeAPSO-34 molecular sieve is prepared by adopting any one of the preparation methods.
Different from the prior art, the technical scheme takes cheap and easily-obtained natural bauxite as a raw material, effectively utilizes resources such as aluminum, silicon, iron, titanium and the like in the natural bauxite, and prepares the bauxite into the composite hierarchical pore with micropore-mesopore and the like and the specific surface area of 250-653 m-doped bauxite in one step by a solid phase method2The MeAPSO-34 molecular sieve (Me ═ Fe, Ti) has the advantages of high raw material utilization rate, low cost, high product yield, simple process and no waste liquid and waste residue, and avoids environmental pollution caused by using nitrate metal salt and the use of a mineralizer HF with high toxicity. The MeAPSO-34(Me ═ Fe, Ti) molecular sieve synthesized by the method has hierarchical pores, large specific surface area and proper pore diameter, so the molecular sieve can be used for preparing HMF and N through denitration reaction in MTO reaction and tail gas treatment and fructose dehydration2/CH4Separation and the like have good application prospect.
Drawings
FIG. 1 is an XRD pattern for examples 1-10;
FIG. 2 is an XRD pattern for examples 11-16;
FIG. 3 is an SEM image of the MeAPSO-34 molecular sieve synthesized in example 5;
FIG. 4 is a graph of the results of an EDX sweep test of the MeAPSO-34 molecular sieve synthesized in example 5;
FIG. 5 is the isothermal adsorption-desorption curve and the pore size distribution diagram of the MeAPSO-34 molecular sieve nitrogen physical adsorption synthesized in example 2;
FIG. 6 is the isothermal adsorption-desorption curve and the pore size distribution diagram of the MeAPSO-34 molecular sieve nitrogen physical adsorption synthesized in example 5;
FIG. 7 is the isothermal adsorption and desorption curves and the pore size distribution diagram of nitrogen physisorption of the MeAPSO-34 molecular sieve synthesized in example 8;
FIG. 8 is a graph showing the isothermal adsorption and desorption curves and the pore size distribution of the MeAPSO-34 molecular sieve nitrogen physisorption synthesized in example 10;
FIG. 9 is the isothermal adsorption and desorption curves and the pore size distribution diagram of nitrogen physisorption of the MeAPSO-34 molecular sieve synthesized in example 12.
Detailed Description
To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.
In this embodiment:
the soil 1 mainly comprises the following components in percentage by mass: al (aluminum)2O3：SiO2：Fe2O3：TiO2＝69.5％：12.2％：17.1％：1.71％；
The soil 2 mainly comprises the following components in percentage by mass: al (Al)2O3：SiO2：Fe2O3：TiO2：TiO2＝72.25％：8.16％：16.85％：1.74％；
The soil 3 mainly comprises the following components in percentage by mass: al (Al)2O3：SiO2：Fe2O3：TiO2＝84.67％：10.6％：2.19％：1.8％；
The soil 4 mainly comprises the following components in percentage by mass: al (Al)2O3：SiO2：Fe2O3：TiO2＝72.25％：8.16％：16.85％：1.74％。
Example 1 preparation of MeAPSO-34 molecular sieves (Me ═ Fe, Ti)
Pretreatment: removing impurities from bauxite, and ball-milling in a ball mill with 500 r.p.m. for 2h to obtain bauxite 1 (soil for short)1) Soil of earth1Roasting in a muffle furnace at 550 ℃ for 4h to obtain the alumina2(soil for short)2)，
Acid treatment: weighing 25g of soil2，63.02gH2C2O4·2H2O, placed in a 1000ml three-necked round bottom flask and 250ml deionized water (C) addedH2C2O41.6673mol/L), refluxing in a water bath kettle at 95 ℃ for 3h to obtain A; after the reflux is finished, transferring the A into a crucible, and drying the A overnight at 110 ℃ to obtain B; calcining B in 550 deg.C muffle furnace for 4 hr to obtain bauxite4(soil for short)4) Soil of earth4The composition percentage ratio of the components is as follows: al (aluminum)2O3：SiO2：Fe2O3：TiO2＝72.25％：8.16％：16.85％：1.74％；
Solid-phase synthesis: 2.3294g of soil are weighed4In a polytetrafluoroethylene lining with H3PO4(85 wt.%) is P2O5Source, silica sol (30 wt%, alkaline) to supplement the SiO2Source, with TEAOH (25 wt%, H)2O) and TEA (99 wt%) as a template; according to the raw material mol ratio of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.44: 2.5818: 0.3939: 23.65, adding 2.0g of deionized water into the polytetrafluoroethylene lining, and performing magnetic stirring for 30min every time one raw material is added to obtain uniform paste after uniform magnetic stirring; crystallization: and (3) placing the polytetrafluoroethylene inner liner in a polytetrafluoroethylene outer kettle added with deionized water, and then placing the polytetrafluoroethylene inner liner in a stainless steel outer kettle to crystallize for 24 hours at 180 ℃. After crystallization, centrifugally washing the product in the lining to pH6.3-6.5 to obtain a precipitate;
and (3) post-treatment: drying the precipitate in a drying oven at 110 ℃ for 2h to obtain molecular sieve raw powder; and (3) roasting the molecular sieve raw powder in a muffle furnace at 550 ℃ for 6h to remove the template agent to obtain the MeAPSO-34 molecular sieve (Me ═ Fe, Ti).
Example 2 (changing crystallization conditions)
The difference between the example 2 and the example 1 is that in the crystallization, the crystallization condition is changed from 24 hours at 180 ℃ to 48 hours at 200 ℃.
Example 3
The differences between example 3 and example 1 are:
example 1 solid phase Synthesis procedure, starting materials in molar ratio of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.44: 2.5818: 0.3939: 23.65 feeding; example 3 solid phase Synthesis of Al in terms of raw Material molar ratio2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.6: 2.6087: 0.3913: 24.98 are fed.
Example 4
The difference between example 4 and example 3 is:
example 3 solid phase Synthesis procedureIn the method, 2.3294g of soil are weighed4(ii) a In the crystallization process, 2.0g of deionized water is added into the polytetrafluoroethylene lining; in the solid phase synthesis of example 4, 1.0g of clay was weighed4B, carrying out the following steps of; during crystallization, 0.8585g of deionized water was added to the polytetrafluoroethylene liner.
Example 5
The difference between example 5 and example 2 is:
EXAMPLE 2 in the course of solid phase synthesis, 2.3294g of soil were weighed4According to the molar ratio of the raw materials of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.44: 2.5818: 0.3939: 23.65 feeding; 2.0g of deionized water was added to the polytetrafluoroethylene liner.
Example 5 in the course of solid phase synthesis, 1.0g of soil was weighed4According to the molar ratio of the raw materials as Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.61: 2.6087: 0.3802: 30.37 charges were made and 1.0g of deionized water was added to the teflon liner.
Example 6
The difference between example 6 and example 1 is:
EXAMPLE 1 solid phase Synthesis procedure 2.3294g of soil were weighed4According to the molar ratio of the raw materials of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O ═ 1.0: 1.0: 0.44: 2.5818: 0.3939: 23.65 feeding; 2.0g of deionized water was added to the polytetrafluoroethylene liner.
Example 6 in the solid phase Synthesis procedure, 1.0g of soil was weighed4According to the raw material mol ratio of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.61: 1.9577: 0.2958: 32.58 charges were made and 1.7172g of deionized water was added to the polytetrafluoroethylene liner.
Example 7
The difference between example 7 and example 5 is:
example 5 solid phase Synthesis procedure, 1.0g of deionized water was added to a polytetrafluoroethylene liner; example 7 solid phase synthesis procedure, 2.0g of deionized water was added to the polytetrafluoroethylene liner.
Example 8
The difference between example 8 and example 5 is:
example 8 solid phase synthesis process, the final material input has 0.22g PEG20000 more.
Example 9
The difference between example 9 and example 5 is: in example 9, the pretreated alumina was not subjected to acid treatment, and the soil was2Directly carrying out solid phase synthesis.
Example 10
Physically screening bauxite, and ball-milling in a ball mill with the rotation speed of 500 revolutions for 2h to obtain the bauxite 1 (called bauxite for short)1) Soil of earth1Roasting in a muffle furnace at 550 ℃ for 4h to obtain the alumina2(soil for short)2) Weighing 25g of soil2，63.02gH2C2O4·2H2Placing the mixture in a 1000ml three-neck round-bottom flask, adding 250ml deionized water, and carrying out reflux treatment in a 95 ℃ water bath for 3h to obtain A; after the reflux is finished, centrifuging the A, washing the A by deionized water until the pH value is about 6.4, and drying the A for 4 hours at 110 ℃ to obtain the alumina3(soil for short)3) Soil of earth3The components in percentage are as follows: al (Al)2O3：SiO2：Fe2O3：TiO2＝84.67％：10.6％：2.19％：1.8％；
With H3PO4(85 wt.%) is P2O5Source, silica sol (30 wt%, alkaline) to supplement the SiO2Source, in TEAOH (25 wt%, H)2O) and TEA (99 wt%) as a template; according to the raw material mol ratio of Al2O3：P2O5：SiO2：TEA：TEAOH：H2O1.0: 1.0: 0.61: 2.6087: 0.3913: 30.37, performing magnetic stirring for 30min every time one raw material is added, uniformly stirring the raw materials by magnetic stirring to form a uniform paste, placing the paste into a reaction kettle added with 1.0g of deionized water, and then placing the reaction kettle into a stainless steel outer kettle; crystallizing at 200 deg.C for 48 h. After crystallization, the product was centrifuged and washed with deionized water to a pH of about6.4; drying in a drying oven at 110 ℃ for 2 h; calcining for 6h in a muffle furnace at 550 ℃ under an air atmosphere to remove the template agent to obtain the MeAPSO-34 molecular sieve (Me ═ Fe, Ti).
Example 11:
the difference between example 11 and example 5 is: in example 11, the pretreated alumina was not subjected to calcination and acid treatment, and the soil was removed1Direct solid phase synthesis, earth1The composition percentage of the components is as follows: al (Al)2O3：SiO2：Fe2O3：TiO269.5%: 12.2%: 17.1%: 1.71 percent; in the crystallization, the crystallization condition is changed from crystallization at 200 ℃ for 48 hours to crystallization at 180 ℃ for 16 hours.
Example 12
The difference between example 12 and example 5 is that the crystallization conditions were changed from 48 hours at 200 ℃ to 16 hours at 180 ℃ in the crystallization.
Example 13
The difference between example 13 and example 5 is: in the crystallization, the crystallization condition is changed from crystallization at 200 ℃ for 48 hours to crystallization at 200 ℃ for 2 hours.
Example 14
The differences between example 14 and example 5 are: in the crystallization, the crystallization condition is changed from crystallization at 200 ℃ for 48 hours to crystallization at 200 ℃ for 72 hours.
Example 15
The difference between example 15 and example 5 is: in the crystallization, the crystallization condition is changed from crystallization at 200 ℃ for 48 hours to crystallization at 140 ℃ for 48 hours.
Example 16
The difference between example 16 and example 5 is: in the crystallization, the crystallization condition is changed from crystallization at 200 ℃ for 48 hours to crystallization at 220 ℃ for 48 hours.
Performance evaluation:
1. mass spectrometry was performed on MeAPSO-34 molecular sieves prepared in examples 1-16 (Me ═ Fe, Ti):
from the XRD patterns of fig. 1, examples 1-10 and fig. 2, examples 11-16, it can be seen that the MeAPSO-34 molecular sieves prepared by this method (Me ═ Fe, Ti) all have characteristic peaks at 2 θ ═ 9.5, 12.9, 16.0, 17.7, 20.6, 24.9, 25.9, 30.6, and 31.0 ° of MeAPSO-34(Me ═ Fe, Ti) (TiAPSO-34 standard PDF:46-0852) and SAPO-34(PDF:47-0429), and there is a tendency to shift left, indicating that metal has entered the framework of the SAPO-34 molecular sieve.
2. SEM image:
FIG. 2 is an SEM image of the MeAPSO-34 molecular sieve synthesized in the example, from which we can see that the morphology of the molecular sieve is cubic, consistent with that reported in the literature, thus indicating that the SAPO-34 molecular sieve is synthesized by the method; it can also be seen from the figure that the particle diameter of the synthesized molecular sieve is about 8 μm;
3. EDX surface scan test results for molecular sieves:
FIG. 3 is a graph of the results of an EDX scanning test of the MeAPSO-34 molecular sieve synthesized in the example, from which it can be seen that the elements Si, P and Al are uniformly distributed, indirectly indicating that these three elements are elements on the framework; in addition, it can be seen that the distribution of Fe element is also very uniform, which means that it may be an element on the framework, while Ti element is not detected and may be too low, and the characterization result of XRD shows that the molecular sieve synthesized by the method is MeAPSO-34(Me ═ Fe, Ti).
4. N2-adsorption/desorption characterization:
and (3) testing conditions are as follows:
the molecular sieve nitrogen physical adsorption performance characterization is carried out by adopting a MacaASAP 2460 type specific surface and porosity analyzer. About 0.1g of the sample was weighed, subjected to vacuum treatment at 200 ℃ and subjected to physical adsorption measurement at a liquid nitrogen temperature (77.3k) using nitrogen gas as an adsorption gas. The BET method and the t-method are respectively adopted for data processing of the specific surface and the micropore part.
| Examples | Specific surface area/(m)2/g) | Pore volume/(cm)3/g) | Aperture-nm |
| Example 2 | 366.3 | 0.210 | 2.36 |
| Example 5 | 423.4 | 0.230 | 2.20 |
| Example 8 | 251.5 | 0.163 | 2.95 |
| Example 9 | 377.2 | 0.231 | 2.45 |
| Example 10 | 492.4 | 0.291 | 2.37 |
| Example 12 | 653.0 | 0.387 | 2.37 |
Example 9 differs from example 5 in that the bauxite of example 9 was not treated with oxalic acid, and from the results of characterization by XRD, it can be seen that the product crystallinity of the non-oxalic acid-treated bauxite for synthesizing molecular sieve was lower relative to that of the oxalic acid-treated bauxite, and from the results of physical adsorption of nitrogen gas, it can be seen that the specific surface area of the molecular sieve synthesized from the non-oxalic acid-treated bauxite was smaller.
Therefore, we can conclude that: the bauxite pretreated by the oxalic acid retains the oxides in the bauxite, is basically an amorphous substance and is beneficial to the synthesis of the molecular sieve; and the bonding phenomenon can not occur in the process of adding phosphoric acid, which is beneficial to the uniformity of the solid-phase synthesis material.
Example 12 is different from example 5 in that crystallization conditions of example 12 are changed from crystallization at 200 ℃ for 48 hours to crystallization at 180 ℃ for 16 hours; the crystallization conditions have a large influence on the specific surface area of the molecular sieve synthesized by the bauxite.
Fig. 5-9 are isothermal adsorption-desorption curves and pore size distribution diagrams of MeAPSO-34(Me ═ Fe, Ti) molecular sieve nitrogen physisorption synthesized in examples 2, 5, 8, 10, 12, respectively, from which we can see that all molecular sieve adsorption-desorption curves synthesized by the method have hysteresis loops, and some of the hysteresis loops are less obvious, indicating that the number of mesopores is less; the isotherms are of type IV in the IUPAC classification, and the hysteresis loop is of type H3. The large adsorption capacity of the high-pressure end of the adsorption-desorption curve indicates that the synthesized molecular sieve has obvious mesoporous characteristics; in addition, there is a significant adsorption phenomenon in the low pressure zone, indicating the presence of micropores; and the existence of large pores (with a pore size R > 50nm) is more evident from the pore size distribution diagram of FIG. 7. The molecular sieve synthesized by the method has a multi-stage pore structure and a large specific surface area through nitrogen adsorption and desorption characterization.
It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising … …" or "comprising … …" does not exclude the presence of additional elements in a process, method, article, or terminal that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the number.
It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.
Claims (7)
1. A preparation method of a MeAPSO-34 molecular sieve is characterized by comprising the following steps:
pretreatment: removing impurities from natural bauxite, ball-milling and roasting to obtain pretreated bauxite;
acid treatment: carrying out acid treatment on the pretreated bauxite by using oxalic acid to obtain an activated bauxite mixture;
solid-phase synthesis: stirring the activated alumina mixture, sequentially adding a phosphorus source, a supplementary silicon source, a template agent and deionized water during stirring, and uniformly stirring to obtain a paste; the templating agent comprises TEA and TEAOH;
and (3) crystallization: crystallizing the paste at 140-220 ℃ until MeAPSO-34 crystals are formed, and centrifugally washing the crystallized material until the pH value of a washing liquid is 6.3-6.5 to obtain a precipitate;
and (3) post-treatment: drying and calcining the precipitate to obtain a MeAPSO-34 molecular sieve;
the natural bauxite contains aluminum element, silicon element, iron element and titanium element;
the activated alumina mixture comprises the following active substances in percentage by mass based on the mixture:
Al2O3：68-85％；SiO2：8-13％；Fe2O3：2-18％；TiO2：1.5-2.0％；
the step of acid treatment also comprises drying and calcining the bauxite after the acid treatment to obtain an activated bauxite mixture; wherein the drying temperature is 110 ℃, and the calcining temperature is 550 ℃;
the solid phase synthesis step, Al in the synthetic material2O3：P2O5：SiO2：TEA：TEAOH：H2The molar ratio of O is 90-110: 90-110: 44-61: 258-261: 29-40: 2365-3258.
2. The method according to claim 1, wherein the solid phase synthesis step further comprises the addition of PEG20000, Al2O3The molar ratio of PEG20000 is 9000-11000: 15-20.
3. The preparation method according to claim 1, wherein in the pretreatment step, the ball milling is carried out for 2 hours in a ball mill rotating at 500 revolutions, and the roasting is carried out for 4 hours in a muffle furnace at 550 ℃.
4. The preparation method of claim 1, wherein in the acid treatment step, the pretreated alumina, oxalic acid and deionized water are mixed, and acid treatment is carried out for 3 hours at 95 ℃, wherein the mass ratio of the pretreated alumina to the oxalic acid to the deionized water is 24-26: 43-48: 230-280.
5. The method as claimed in claim 1, wherein the crystallization step is carried out for a crystallization time of 2 to 72 hours.
6. The method according to claim 1, wherein the post-treatment step comprises drying the precipitate in an oven at 110 ℃ for 2 hours and calcining the precipitate in a muffle furnace at 550 ℃ for 6 hours under an air atmosphere.
7. A MeAPSO-34 molecular sieve, characterized in that the MeAPSO-34 molecular sieve is prepared by the preparation method according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910275358.8A CN110040744B (en) | 2019-04-08 | 2019-04-08 | MeAPSO-34 molecular sieve and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910275358.8A CN110040744B (en) | 2019-04-08 | 2019-04-08 | MeAPSO-34 molecular sieve and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110040744A CN110040744A (en) | 2019-07-23 |
| CN110040744B true CN110040744B (en) | 2022-07-01 |
Family
ID=67276345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910275358.8A Active CN110040744B (en) | 2019-04-08 | 2019-04-08 | MeAPSO-34 molecular sieve and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110040744B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113479900B (en) * | 2021-08-20 | 2023-01-10 | 中化泉州能源科技有限责任公司 | Method for preparing step pore molecular sieve by using natural bauxite |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101450806A (en) * | 2007-12-05 | 2009-06-10 | 中国科学院大连化学物理研究所 | AEI/CHA eutectic molecular sieve containing triethylamine and synthetic method thereof |
| CN104030315A (en) * | 2014-06-25 | 2014-09-10 | 常州大学 | Method for synthesizing heteroatom aluminophosphate molecular sieve by utilizing natural ore |
| CN104108726A (en) * | 2013-04-16 | 2014-10-22 | 中国石油化工股份有限公司 | Silicoaluminophosphate molecular sieve with high silica-alumina ratio and CHA structure, and synthetic method thereof |
| CN108147427A (en) * | 2016-12-05 | 2018-06-12 | 中国科学院大连化学物理研究所 | A kind of CHA types hetero atom Metal-aluminophosphate Molecular Siever and preforming synthetic method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102010055679A1 (en) * | 2010-12-22 | 2012-06-28 | Süd-Chemie AG | Titano-silico-alumino-phosphate |
-
2019
- 2019-04-08 CN CN201910275358.8A patent/CN110040744B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101450806A (en) * | 2007-12-05 | 2009-06-10 | 中国科学院大连化学物理研究所 | AEI/CHA eutectic molecular sieve containing triethylamine and synthetic method thereof |
| CN104108726A (en) * | 2013-04-16 | 2014-10-22 | 中国石油化工股份有限公司 | Silicoaluminophosphate molecular sieve with high silica-alumina ratio and CHA structure, and synthetic method thereof |
| CN104030315A (en) * | 2014-06-25 | 2014-09-10 | 常州大学 | Method for synthesizing heteroatom aluminophosphate molecular sieve by utilizing natural ore |
| CN108147427A (en) * | 2016-12-05 | 2018-06-12 | 中国科学院大连化学物理研究所 | A kind of CHA types hetero atom Metal-aluminophosphate Molecular Siever and preforming synthetic method |
Non-Patent Citations (3)
| Title |
|---|
| "Dehydration of fructose to 5-hydroxymethylfurfural over MeSAPOs synthesized from bauxite";Xueni Sun et al.;《MICROPOROUS AND MESOPOROUS MATERIALS》;20171013;第259卷;第238-243页 * |
| "赤泥在环境修复领域的应用综述";练佳佳等;《硅酸盐通报》;20151115(第11期);第3236-3242页 * |
| "铝磷酸盐分子筛材料的研究进展";王靖宇等;《黄山学院学报》;20061020(第05期);第29-32页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110040744A (en) | 2019-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109250729B (en) | Cu-SAPO-34 molecular sieve synthesis method, synthesized molecular sieve and application | |
| CN109250728B (en) | Cu-SAPO molecular sieve synthesis method, synthesized Cu-SAPO molecular sieve and application | |
| CN110668458B (en) | Al-SBA-15 mesoporous molecular sieve, denitration catalyst, preparation methods of Al-SBA-15 mesoporous molecular sieve and denitration catalyst, and application of Al-SBA-15 mesoporous molecular sieve and denitration catalyst | |
| CN107434252B (en) | Preparation method of low-silicon nano SAPO-34 molecular sieve | |
| Xiao et al. | Facile synthesis of mesoporous sulfated Ce/TiO 2 nanofiber solid superacid with nanocrystalline frameworks by using collagen fibers as a biotemplate and its application in esterification | |
| CN105381812B (en) | A kind of method for preparing the composite semiconductor material with meso-hole structure | |
| CN113058633A (en) | Boron nitride hollow composite material and preparation method and application thereof | |
| CN106799202A (en) | A kind of molecular sieve for for gas separate and its preparation and application | |
| Hou et al. | Activated carbon aerogel supported copper catalysts for the hydrogenation of methyl acetate to ethanol: effect of KOH activation | |
| CN106032282A (en) | Preparation method and applications of mordenite having mesopores and micropores | |
| CN108975349A (en) | A kind of compound ZSM-5 molecular sieve of macropore-micropore and its synthesis and application | |
| CN110040744B (en) | MeAPSO-34 molecular sieve and preparation method thereof | |
| CN108502897A (en) | A kind of photochemistry green synthesis method of Zr doping SBA-15 meso-porous molecular sieve materials | |
| CN106276964B (en) | A kind of transgranular phosphorous ZSM-5 molecular sieve and preparation method thereof | |
| KR101940851B1 (en) | Silicoaluminophosphate, method for producing same, and solid acid catalyst comprising same | |
| CN109574036B (en) | Preparation method of DNL-1 molecular sieve | |
| Jiang et al. | Facile morphology control of 3D porous CeO 2 for CO oxidation | |
| Wang et al. | Keggin structure and surface acidity of 12-phosphotungstic acid grafted Zr-MCM-48 mesoporous molecular sieves | |
| CN108584977A (en) | The method of one step green syt cobalt doped SBA-15 meso-porous molecular sieve materials | |
| CN112456511B (en) | SAPO-34 molecular sieve, and preparation method and application thereof | |
| CN110668465A (en) | MeAPSO-44 molecular sieve and preparation method thereof | |
| CN108996517B (en) | Hierarchical-pore wide-silica-alumina-ratio EU-1 molecular sieve and preparation method thereof | |
| CN106395854A (en) | Preparation method of phosphorus modified multistage pore ZSM-5 zeolite | |
| CN106140246B (en) | A kind of ethane Selective Oxidation ethylene catalyst and the preparation method and application thereof | |
| Yang et al. | Synthesis of mesoporous γ-alumina and its catalytic performance in dichloropropanol cyclization |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |