41 results about "Isomorphous substitution" patented technology

The invention relates to a method used for preparing zeolite molecular sieve containing titanium by modification of natural zeolite, and uses the natural zeolite as a raw material and the zeolite molecular sieve containing titanium is obtained through ion exchange, chemical dealumnization treatment and gas-solid isomorphous substitution reaction. The mole ratio of Si and Ti of molecular sieve skeleton is 20 to 100. The invention brings metallic titanium which has special catalytic performance to the skeleton of the natural zeolite, which greatly promotes grade of natural zeolite products, widens the application range of the natural zeolite and provides a way with low cost, convenient operation and environment protection to prepare heteroatom zeolite molecular sieve.

The invention discloses a preparation method of a highly dispersed hierarchical pore H-ZSM-5 molecular sieve of a framework metal. The preparation method comprises the following steps: treating carbonblack by oxidation treatment to prepare hydrophilic carbon black as a hard template; preparing a nanoscale double metal specie by a space limitation method as a metal source of doping the framework;synthesizing a metal framework doped hierarchical pore H-ZSM-5 molecular sieve by one-step in-situ hydro-thermal synthesis; and preparing an H type molecular sieve by means of Na type molecular sieveion exchange. The H-ZSM-5 molecular sieve prepared by the method retains the advantages of a microporous molecular sieve and regular mesoporous ducts are added in the structure, so that the mass transfer performance of the molecular sieve is improved. The method solves the problems of degree of crystallinity and destroy of active center of a parent body of the molecular sieve as a result of a post-treatment method. The active metal sites of the molecular sieve are increased by isomorphous substitution of the nano metal specie, so that the reaction performance of the catalyst is improved. The dosage of a reagent caused by regulating / modifying the molecular sieve structure for many times is saved, and the catalyst preparation process flow is shortened.

The invention relates to the preparation of novel bi- or tri metallic silicate micro-porous and / or meso-porous materials based on cerium, nickel, copper and / or zinc on a porous silicate framework matrix to use its molecular sieve effect to target preferentially the acidic organic molecules present in hydrocarbon feedstocks like crude oil, bitumen, VGO and the like. The chosen metals are selected based on their ability to activate steam and transfer oxygen for completing the oxidation of carboxylic compounds or decarboxylating them. These composite materials can be prepared under hydrothermal synthesis conditions in order to produce suitable porous solids where the metals are well dispersed and preferentially distributed inside the channels of the silicate framework where they can interact only with the molecules that can go inside the channels. According to the invention, the metallo-silicate materials are prepared under hydrothermal synthesis conditions Modification of the physical-chemical properties of the porous silicate materials can be accomplished by partial replacement of the silicon atoms by cerium, nickel, copper and / or zinc atoms in the material by isomorphous substitutions of these elements in a synthesis gel or by post-synthesis modifications like ion-exchange or impregnation / deposition. The materials can be used as prepared catalysts for the steam catalytic reduction of the total acid number (TAN) in acidic crude oil feedstocks and in the presence of steam and / or CO2 as oxidizing agent to complete decarboxylation and to keep the metal oxide active sites from reducing and deactivating as well as other partial upgrading reactions.

The invention relates to a preparation method of a low-impurity-content copper-based methanol synthesis catalyst, belonging to the technical field of catalyst preparation. The preparation method comprises the following steps: adding a nitrate solution (containing Cu<2+>, Zn<2+> and Al<3+>) and an alkaline precipitator in water in a parallel flow manner; after a neutralization reaction is finished, performing hydrothermal ageing treatment for 1-4h, washing, filtering, drying, roasting, and finally tabletting and forming to obtain the catalyst. The preparation method has the beneficial effects that by adopting a hydrothermal ageing treatment technology, the crystallization and Cu-Zn isomorphous substitution progress of amorphous precipitate are accelerated, so that impurity ions are easily removed by water washing and the finally obtained catalyst has relatively high methanol synthesis catalytic activity and thermal stability.

The invention relates to a nanoscale lamellar rare-earth hydroxide functional material and a preparation method thereof. According to the invention, the characteristic that metal ions are uniformly distributed in a lamellar rare-earth hydroxide laminate is utilized, rare-earth metal ions with similar radiuses are selected for carrying out isomorphous substitution, and a polyethyleneimine synthesis method is adopted for preparing the lamellar compound rare-earth hydroxide with the chemical formula of being RE2(OH)5Cl nH2O. Dimension of the prepared rare-earth hydroxide can be adjusted within the range from nanometer to micrometer, and isomorphous substitution by virtue of different rare-earth ions is carried out, thus a product can have a bright fluorescent light (blue light to near infrared light) with adjustable emission wavelength. According to the invention, a compound lamellar optical functional material system with uniform composition, adjustable dimension, good crystallinity, laminate rare earth ions which can be doped and exchangeable interlayer anions is constructed, and the preparation method is simple, practicable, rapid and convenient.

A preparation method of an L zeolite containing gallium. The method comprises steps of: preparing silicon source, aluminium source, gallium source, alkali source and water into an initial reaction mixture according to a certain feeding sequence and a method, wherein a total molar ratio of K2O: Al2O3:Ga2O3:SiO2:H2O equal to 2-20:0-1:0.01-1:6-18:40-400; crystallizing in a seal reaction kettle under hydro-thermal condition at a crystallization temperature of 120-200 DEG C for 1-192 h; filtering, washing, drying and roasting the crystallization products to obtain L zeolite with aluminium partially substituted or completely substituted by gallium in isomorphous substitution. The product has regular discoid morphology; and a catalyst prepared by using the L zeolite containing gallium has potential application prospect in alkane conversion reaction.

The invention relates to a preparation method of a lithium cobaltate electrolyte for inhibiting lithium dendrite growth, the method is simple and easy to operate, low in cost and short in time; according to the method, an inorganic electrolyte excellent in electrochemical performances can be obtained by doping of Nb ions in a positive electrode material and isomorphous substitution of Co ion sitesin lattices of the positive electrode material to change parameters of the lattices; and a light carbon-nitrogen polymer as a filler is uniformly mixed with the electrolyte to form a solid electrolyte which can be used for suppression of lithium dendrite growth in lithium metal batteries.

The invention discloses a method for preparing a hierarchical porous isomorphous substitution Ga-ZSM-5 molecular sieve catalyst. The method comprises the following steps: tetraethyl orthosilicate, gallium nitrate, aluminum isopropoxide, tetrapropylammonium hydroxide (TPAOH), hexadecyltrimethoxysilane (HTS) and ethanol are mixed according to a certain ratio, and are stirred until a gel is formed, and the gel is crystallized, reacted and calcined to obtain the catalyst. The catalyst has the advantages of excellent effect, high benzene conversion activity, high toluene and xylene selectivity, high stability and low ethylbenzene selectivity when used in an alkylation reaction of benzene with methanol to synthesize toluene and xylene; and other metals or hydrogen atmosphere is not needed, so the separation of the ethylbenzene byproduct is omitted, the production cost and the energy consumption, are reduced, and the increase of the economical property of a process route for the alkylation ofbenzene and methanol to prepare toluene and xylene is facilitated.

The invention relates to a niobium modified lithium cobalt oxide anode material preparation method. The method is simple and easy in operation, low in cost and low in time consumption. Nb ions are doped in an anode material to realize isomorphous substitution of Co ion sites in lattices of the anode material to change lattice parameters, so that the anode material excellent in electrochemical performance is obtained. The porosity characteristic of a carbon-silicon coating material is beneficial to electrolyte absorption and storage, and a space is provided for volume expansion of a silicon material in a charging-discharging process; due to nanoscale size of porous silicon, relief of volume effect of silicon particles is realized. Therefore, high reversible capacity, great cycle performance and excellent rate capability are realized.

A catalyst for naphtha catalytic cracking to prepare ethylene and propylene is disclosed. Based on the weight content of the catalyst, the catalyst comprises 40-90% of an MFI molecular sieve subjected to metal isomorphous substitution, 0.1-2.5% of a rare earth metal oxide and 0.2-2.0% of heteropoly acid. In the molecular sieve, Al in the molecular sieve is all or partially substituted by a metal, and the substituting metal is one or more selected from magnesium, calcium, zinc, gallium, and the like. A preparing method of the catalyst includes (1) substituting all or a part of the Al in the ZSM-5 molecular sieve by the selected substituting metal to prepare the ZSM-5 molecular sieve subjected to metal isomorphous substitution, (2) selecting a proper adhesive, pulping a proper amount of the heteropoly acid, a proper amount of the adhesive and the ZSM-5 molecular sieve subjected to metal isomorphous substitution in the step (1) to prepare a suspension, drying the suspension and then performing strip extrusion and molding, and (3) performing loading of the rare earth metal oxide through a hot-carrier dipping method, and drying the product after dipping to obtain the final catalyst. The catalyst has advantages of high alkene yields, low reaction temperatures, good catalyst stability, and the like.

The invention discloses a Ce isomorphous substitution LTL molecular sieve and a preparation method thereof. The preparation method of the Ce isomorphous substitution LTL molecular sieve comprises thefollowing steps that cerium source, potassium source, silicon source, aluminum source and water are mixed to obtain colloidal sol; the colloidal sol is aged and crystallized in turn, and obtained solid is treated and roasted in turn to obtain the Ce isomorphous substitution LTL molecular sieve. The molecular sieve product prepared by the method has higher crystallinity and a more regular shape; inthe product prepared by the method, cerium components are existed in the molecular sieve in the form of cage-construction cerium; the molecular sieve can be used for a carrier of a C6-C8 hydrocarbonalkyl aromatization reaction to significantly improve the hydrocarbon yield and liquid yield of the aromatization reaction, and has good industrialization prospects.

The invention discloses an ultra-stable mineralizing agent and application thereof in remediation of heavy metal contaminated soil. The ultra-stable mineralizing agent is prepared by quickly adding anenvironment-friendly metal ion solution and a precipitant into a micro-liquid membrane reactor; the use process can be implemented in a sowing or slurry spraying mode. The ultra-stable mineralizing agent is slightly alkalescent, does not cause soil acidification, and is very suitable for southern areas with serious soil pollution. Comparing adsorbent, the ultra-stable mineralizing agent preparedby the invention has very high activity; heavy metal ions such as copper, cadmium and manganese in soil can be quickly anchored in crystal lattices of the ultra-stable mineralizing agent in an isomorphous substitution or dissolution-reconstruction mode, hydrotalcite with a more stable structure is formed through mineralization, and the heavy metal ions are extremely difficult to dissociate from the hydrotalcite and are in an ultra-stable mineralization state. Besides, due to the ion radius matching rule, the ultra-stable mineralizing agent prepared by the invention also shows good selectivityand has a very good effect in in-situ remediation of soil heavy metal pollution.

The invention discloses a metal-modified SAPO-5 / SAPO-34 composite molecular sieve, particularly, metal-modified lanthanide series metal isomorphous substitution. The invention further discloses a preparation method of the metal-modified SAPO-5 / SAPO-34 composite molecular sieve. When the metal-modified SAPO-5 / SAPO-34 composite molecular sieve is used for a reaction of preparing low carbon olefins by using organic oxygen-containing compounds, the composite molecular sieve has favorable catalytic activity, excellent propylene and butene selectivity and long service life.

The invention discloses a Ce isomorphous substitution LTL molecular sieve and a preparation method thereof. The preparation method of the Ce isomorphous substitution LTL molecular sieve comprises thefollowing steps that cerium source, potassium source, silicon source, aluminum source and water are mixed to obtain colloidal sol; the colloidal sol is aged and crystallized in turn, and obtained solid is treated and roasted in turn to obtain the Ce isomorphous substitution LTL molecular sieve. The molecular sieve product prepared by the method has higher crystallinity and a more regular shape; inthe product prepared by the method, cerium components are existed in the molecular sieve in the form of cage-construction cerium; the molecular sieve can be used for a carrier of a C6-C8 hydrocarbonalkyl aromatization reaction to significantly improve the hydrocarbon yield and liquid yield of the aromatization reaction, and has good industrialization prospects.

The invention relates to the preparation of novel bi- or tri metallic silicate micro-porous and / or meso-porous materials based on cerium, nickel, copper and / or zinc on a porous silicate framework matrix to use its molecular sieve effect to target preferentially the acidic organic molecules present in hydrocarbon feedstocks like crude oil, bitumen, VGO and the like. The chosen metals are selected based on their ability to activate steam and transfer oxygen for completing the oxidation of carboxylic compounds or decarboxylating them. These composite materials can be prepared under hydrothermal synthesis conditions in order to produce suitable porous solids where the metals are well dispersed and preferentially distributed inside the channels of the silicate framework where they can interact only with the molecules that can go inside the channels. According to the invention, the metallo-silicate materials are prepared under hydrothermal synthesis conditions Modification of the physical-chemical properties of the porous silicate materials can be accomplished by partial replacement of the silicon atoms by cerium, nickel, copper and / or zinc atoms in the material by isomorphous substitutions of these elements in a synthesis gel or by post-synthesis modifications like ion-exchange or impregnation / deposition. The materials can be used as prepared catalysts for the steam catalytic reduction of the total acid number (TAN) in acidic crude oil feedstocks and in the presence of steam and / or CO2 as oxidizing agent to complete decarboxylation and to keep the metal oxide active sites from reducing and deactivating as well as other partial upgrading reactions.

An agent for searching for protein crystallization conditions, containing a water-swellable layered silicate having a fluorine atom and a hydroxyl group, wherein the fluorine atom is covalently bonded to the silicate by isomorphous substitution with the hydroxyl group. A method of searching for protein crystallization conditions, which comprises a step of mixing the agent for searching for protein crystallization conditions described above and a solution in which a protein is dissolved.

The disclosure describes a new class of isomorphously metal-substituted aluminophosphate materials with high phase purity that are capable of performing selective Brönsted acid catalyzed chemical transformations, such as transforming alcohols to olefins, with high conversions and selectivities using mild conditions. Isomorphous substitutions of functional metal ions for both the aluminum ions and the phosphorous ions were successful in various AlPO structures, along with multiple metal substitutions into a single aluminum site and / or a phosphorous site. This invention can be used towards the catalytic conversion of hydroxylated compounds of linear and / or branched moiety with the possibility of being substituted to their respective hydrocarbon products, preferably light olefins containing 2 to 10 carbon atoms, among other chemistries.

The invention relates to the field of catalytic cracking catalyst preparation, and discloses a catalytic cracking catalyst and a preparation method thereof. The method comprises the following steps: sequentially carrying out ion exchange reaction, hydro-thermal ultra-stabilization treatment, first roasting, gas-phase chemical isomorphous substitution reaction, and gas-solid separation on a NaY molecular sieve, so as to obtain a modified molecular sieve, then carrying out gelling on the obtained modified molecular sieve with clay and an adhesive, and sequentially carrying out drying and secondary roasting on the obtained gelling product, wherein the temperature of the molecular sieve subjected to the first roasting is 350-600 DEG C through the hydro-thermal ultra-stabilization treatment andthe first roasting method, and the solid content is not lower than 98 wt%. The preparation method provided by the invention is simple in process flow, the production energy consumption of the catalytic cracking catalyst is greatly reduced, and the prepared catalytic cracking catalyst has relatively high conversion rate, light-oil yield and liquid yield, and has relatively low coke selectivity.

The invention discloses a preparation method for a tin-doped mesoporous silica smoke suppressant, comprising the following steps of: doping an active component, namely, tin, in the framework of mesoporous silica via a hydrothermal isomorphous substitution method, roasting, and then obtaining the tin-doped mesoporous silica smoke suppressant. The smoke suppressant has a high specific surface area, and an adsorption effect on the smoke toxic gas released during a flame-retardant process; simultaneously, the active components, namely, tin atoms, of the smoke suppressant are located in the framework of mesoporous silica, and have a catalytic conversion effect on the smoke toxic gas released during the flame-retardant process; additionally, the tin-doped mesoporous silica is good in heat stability, capable of protecting a carbon layer to be stable, and good in synergistic flame-retardant effect. The tin-doped mesoporous silica smoke suppressant can be widely applied to flame retardance, smoke suppression and toxicity reduction for the materials of wood, high-molecular materials, paper, braided fabrics, and the like in case of being compounded with phosphorus-nitrogen flame retardants.

The invention relates to a preparation method for a microwave phosphorus ammonium type zeolite material for desulfurization waste water. The preparation method comprises the steps of (1) adding granular natural clinoptilolite into ammonium ion I type compound liquid for hydrothermal modification for 24 hours, and preparing ammonium type zeolites after flushing and drying; (2) dipping and washing the ammonium type zeolites in strong phosphoric acid, and drying the ammonium type zeolites for 6 hours; (3) putting the dried ammonium type zeolites in a microwave generator to conducting a solid-liquid phase isomorphous substitution reaction, washing and drying a product to prepare the microwave phosphorus modified ammonium type zeolites. The number of internal adsorption ducts of the microwave phosphorus ammonium type zeolites is increased, the adsorption caliber is increased, the structure is the structural basis of zeolite anion exchange, negative ions in the water can be removed through ion exchange, and the capacity of adsorbing organisms in the desulfurization waste water is greatly improved.

The disclosure describes a new class of isomorphously metal-substituted aluminophosphate materials with high phase purity that are capable of performing selective Brönsted acid catalyzed chemical transformations, such as transforming alcohols to olefins, with high conversions and selectivities using mild conditions. Isomorphous substitutions of functional metal ions for both the aluminum ions and the phosphorous ions were successful in various AlPO structures, along with multiple metal substitutions into a single aluminum site and / or a phosphorous site. This invention can be used towards the catalytic conversion of hydroxylated compounds of linear and / or branched moiety with the possibility of being substituted to their respective hydrocarbon products, preferably light olefins containing 2 to 10 carbon atoms, among other chemistries.

The invention relates to a preparation method of a lithium ion conductor-coated lithium cobaltate positive electrode material. The method is simple and easy to operate and is low in cost and short inconsumed time. According to the method, Nb ions are doped into the positive electrode material, isomorphous substitution is performed on Co ion sites in positive electrode material lattices, the lattice parameter is changed, and the electrochemical performance is favorable. After an inorganic rapid-lithium ion conductor precursor solution and a lithium ion battery positive electrode material are uniformly mixed under a certain temperature, the lithium ion battery positive electrode material of which a surface is coated with rapid-lithium ion conductor colloid is obtained, a uniform coating layer is formed on a surface of a positive electrode particle after thermal processing on the lithium ion battery positive electrode material of which the surface is coated with rapid-lithium ion conductor colloid, the transmission activity of lithium ions in the electrode material can be improved, an interface between an electrolyte and a positive electrode is improved, and the battery performance is improved.

The invention provides a preparation method of a stepped hole heteroatom M-Beta molecular sieve. Compared with an existing synthesis method, the method has the advantages that the M-Beta molecular sieve can be directly synthesized through a one-step steam-assisted method, and the inherent defects of traditional hydrothermal synthesis are overcome. Compared with the existing M-Beta synthesis method, the method has the advantages that the M-Beta molecular sieve with a regular morphology and a stepped pore structure can be synthesized without a nuclear promoter aluminum and a high-corrosivity crystallization aid hydrofluoric acid; the synthesis time is reduced to 48 hours, the steps are simple, and the energy consumption can be effectively reduced; little crystallization liquid is generated so that the pollution problem of a large amount of crystallization waste liquid can be effectively avoided; meanwhile, the problem that a large amount of waste acid is discharged due to the fact that strong acid must be used for pretreatment in a traditional secondary isomorphous substitution method and an aluminum-containing one-step synthesis method is solved.

The invention discloses a method for preparing anti-caking high-purity electronic-grade strontium nitrate and belongs to the technical field of strontium nitrate preparation. Strontianite and witherite are crushed and pulped and then nitric acid is added for reaction, and a nitric acid solution is generated; then, a sodium hydroxide solution is added into the nitric acid solution, and calcium hydroxide precipitate is generated through reaction; then, supernate is collected through centrifugal separation, nitric acid is added, and a filtered solution is obtained through reaction, curing and filtering; finally, the obtained filtered solution is subjected to cooling crystallization, impurity removal, filtering, evaporation crystallization and drying, and the anti-caking high-purity electronic-grade strontium nitrate is obtained. Examples show that operation is easy and convenient, and the isomorphous substitution phenomenon can not occur in the preparation process. Besides, the prepared strontium nitrate is high in purity, low in impurity content, not prone to caking, capable of reducing production and use cost of clients and worthy of large-scale production and application.

The invention relates to a preparation method of a novel ammonium type zeolite material for treating desulfurization wastewater. The preparation method comprises the following steps: (1) feeding 1-1.5 weight parts of ammonium type zeolite into 3-5 weight parts of concentrated phosphoric acid at 30 DEG C, and soaking for 5-6 hours; (2) flushing the soaked ammonium type zeolite for 3 times, and drying for 6 hours at 105 DEG C; (3) putting the dried ammonium type zeolite into a microwave generator, performing solid-liquid phase isomorphous substitution reaction for 18 hours, flushing a product for 3 times, and drying for 6 hours at 105 DEG C to prepare microwave phosphorus modified ammonium type zeolite; and (4) hydrothermally mixing the microwave phosphorus modified ammonium type zeolite with 4-5 weight parts of compound liquid of CPB and BS-12 for 8 hours, flushing a product for 5 times, and drying for 6-8 hours to prepare compound surfactant modified ammonium type zeolite. The novel ammonium type zeolite disclosed by the invention has relatively high adsorption capacity on organic matters in the desulfurization wastewater, and can also be subjected to quantitative analysis.

The invention discloses a bismuth-based composite photocatalyst as well as a preparation method and application thereof, and belongs to the field of photocatalysis. The component of the photocatalyst is S-BiOBr / Bi2Sn2O7, thiourea is selected as a sulfur source to be doped with bismuth oxybromide, and then bismuth stannate prepared by taking bismuth nitrate pentahydrate and tin tetrachloride pentahydrate as a bismuth source and a tin source is modified. According to the preparation method, the S-doped BiOBr nanosheet is successfully prepared by adopting isomorphous substitution and hydrothermal method self-assembly, and then Bi2Sn2O7 is attached to the surface of the S-doped BiOBr nanosheet, so that the 3D / 0D interface Z-type S-BiOBr / Bi2Sn2O7 heterojunction is constructed. The preparation method has the advantages of easily available raw materials, simple process, convenient operation, greenness and environmental protection, and the prepared photocatalyst has excellent degradation performance and good stability and can be recycled. The method can be widely applied to degradation of pollutants such as dyes, antibiotics and algae.

The invention discloses a preparation method and application of modified Y molecular sieve and a single-stage hydrocracking catalyst. The method includes the following contents: (1) using NaY zeolite as raw powder to carry out ammonium salt ion exchange; (2) carrying out dealumination and silicon filling treatment on the Y molecular sieve of step (1); (3) treating the Y after step (2) The molecular sieve is subjected to hydrothermal treatment; (4) the Y molecular sieve treated in step (3) is subjected to acid dealumination treatment; (5) the Y molecular sieve obtained in step (4) is rapidly dried; (6) the Y obtained in step (5) is The molecular sieve undergoes a carbon deposition reaction; (7) the molecular sieve obtained in step (6) is desiliconized; (8) the Y molecular sieve after desiliconization in step (5) is filtered and dried, and then subjected to charcoal treatment to obtain the modified Y molecular sieve. Y molecular sieve. The single-stage hydrocracking catalyst prepared by the modified Y molecular sieve prepared by the method of the present invention is used in the single-stage hydrocracking process and has good reactivity and nitrogen resistance.

The invention relates to a hydrotalcite-like iron-promoted nickel-based catalyst for hydrogen production by autothermal reforming of acetic acid and a preparation method. The present invention aims at the problems that the existing catalyst changes in the catalyst structure and the oxidation and sintering of active components during the autothermal reforming of acetic acid, resulting in catalyst deactivation, and provides a catalyst that is resistant to oxidation, sintering, coking, and has high activity. new catalyst. The chemical component of the catalyst of the present invention is (ZnO) a (NiO) b (AlO 1.5 ) c (FeO 1.5 ) d , where a is 0.75‑3.25, b is 0.25‑0.75, c is 0‑1.0 and d is 0‑1.0. The present invention uses a co-precipitation method to prepare a Zn-Al carbonate-type hydrotalcite-like structure as a precursor, and introduces the active component nickel and the additive iron. Through the isomorphous substitution of nickel for zinc and iron for aluminum, it enters the Hydrotalcite-like structural position; the composite oxide obtained by roasting effectively inhibits the possible migration, aggregation, oxidation and sintering of the active component nickel under high-temperature reaction conditions, thus improving the activity and stability of the catalyst.

The invention discloses a metal-modified SAPO-5 / SAPO-34 composite molecular sieve, particularly, metal-modified lanthanide series metal isomorphous substitution. The invention further discloses a preparation method of the metal-modified SAPO-5 / SAPO-34 composite molecular sieve. When the metal-modified SAPO-5 / SAPO-34 composite molecular sieve is used for a reaction of preparing low carbon olefins by using organic oxygen-containing compounds, the composite molecular sieve has favorable catalytic activity, excellent propylene and butene selectivity and long service life.

The invention discloses a synthesis method of a Ga isomorphous substituted nanometer GaZSM-22 molecular sieve, and relates to a synthesis method of the nanometer GaZSM-22 molecular sieve. The invention aims to solve the problem that a GaZSM-22 molecular sieve prepared through an existing method is large in size. The synthesis method comprises the steps of (1) mixed gel preparation and (2) crystallization, wherein the Ga isomorphous substituted nanometer GaZSM-22 molecular sieve is obtained. The synthesis method has the beneficial effects that the Ga isomorphous substituted nanometer GaZSM-22 molecular sieve is rodlike nanometer crystals, the particle size is 20-50 nm, the grain length is 50-100 nm, a ratio of silicon to gallium is (25 to 45) to 1, and a molecular sieve skeleton does not contain aluminium atoms. The synthesis method is mainly used for conducting Ga isomorphous substitution to synthesize the nanometer GaZSM-22 molecular sieve.