CN107974274B

CN107974274B - Phosphorus-containing and metal-loaded MFI structure molecular sieve and preparation method thereof

Info

Publication number: CN107974274B
Application number: CN201610920398.XA
Authority: CN
Inventors: 欧阳颖; 罗一斌; 庄立; 刘建强; 舒兴田
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petrochemical Corp
Priority date: 2016-10-21
Filing date: 2016-10-21
Publication date: 2020-01-10
Anticipated expiration: 2036-10-21
Also published as: CN107974274A

Abstract

The present disclosure provides a phosphorus-containing and metal-loaded MFI structure molecular sieve and its preparation method, n (SiO) of said molecular sieve₂)/n(Al₂O₃) Greater than 100; the phosphorus content of the molecular sieve is 0.1-5 wt%; the content of the load metal of the molecular sieve is 0.5-5 wt%; the molecular sieve has an Al distribution parameter D (Al) satisfying: d is more than or equal to 0.5 and less than or equal to 0.8 (Al); the molecular sieve has a supported metal distribution parameter D (M) satisfying: d is more than or equal to 2 and less than or equal to 10 (M); the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 15-30% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60-80%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100. The MFI structure molecular sieve containing phosphorus and loaded metal is used as an active component to prepare a catalyst or an auxiliary agent, so that the yield and the octane number of gasoline can be improved in the catalytic cracking reaction of petroleum hydrocarbon, and the olefin content of the gasoline can be effectively reduced.

Description

Phosphorus-containing and metal-loaded MFI structure molecular sieve and preparation method thereof

Technical Field

The disclosure relates to an MFI structure molecular sieve containing phosphorus and loaded metal and a preparation method thereof.

Background

With the continuous upgrade of gasoline standards in China, the control on the olefin content of gasoline is stricter. The olefin content of the gasoline is limited to be not higher than 28% by volume percent by the national fourth standard, and the olefin content of the national fifth gasoline standard is further reduced to be not higher than 24% by volume percent. In developed countries such as Europe and America, the gasoline standard is more strict on the content of olefin, for example, California 3 standard limits the content of olefin in gasoline to be not higher than 6% by volume fraction, and Europe and Pentium standard is not higher than 18% by volume fraction.

The catalytic cracking gasoline accounts for more than 60% of the gasoline pool composition in China, and the high olefin content in the catalytic cracking gasoline becomes one of the bottlenecks of entering the gasoline pool. On the large background of improving the yield of the light oil, the yield of the light oil can be greatly improved (more than 8%) by a catalytic cracking wax oil (FGO) selective hydrotreating process and a selective catalytic cracking (mild cracking) process integration technology (IHCC) developed by a stone institute, but the olefin content of a gasoline fraction of the IHCC process is higher (up to 55%) than that of the conventional FCC, so that the reduction of the olefin content of the catalytic cracking gasoline becomes an urgent matter.

The ZSM-5 molecular sieve has shape selective cracking and isomerization functions, is flexibly used in a catalytic cracking catalyst or an auxiliary agent, and can effectively improve the octane number of catalytic cracking gasoline. The ZSM-5 molecular sieve is a three-dimensional mesoporous high-silicon molecular sieve which is successfully prepared by Mobil corporation firstly, ten-membered ring channels are arranged in the directions of [100] and [010], the pore diameter is about 0.51nm multiplied by 0.55nm and 0.53nm multiplied by 0.56nm, and the efficient shape-selective catalytic property is caused by a unique Z channel in the direction of [100 ]. Allowing linear paraffins to enter while limiting multi-sided and cyclic hydrocarbons, preferentially cracking low octane paraffins and olefins in gasoline to C3 and C4 olefins, while isomerizing linear olefins to high octane olefins with more side chains. The ZSM-5 molecular sieve is applied to a catalytic cracking catalyst, so that the yield of liquefied gas and the concentration of propylene in the liquefied gas are improved on one hand, and the octane number of gasoline is improved on the other hand. However, since part of gasoline olefin is converted into liquefied gas, the loss of gasoline yield is inevitably brought, and in order to produce high-octane gasoline, a ZSM-5 molecular sieve is necessary to be modified, the cracking capability is reduced, the aromatization capability is improved, and the olefin component in the gasoline is converted into an aromatic hydrocarbon component.

Chinese patent CN1080313A discloses a catalytic upgrading-aromatization method for inferior gasoline, wherein the catalyst is Zn-Al or Zn-Al-rare earth modified HZSM-5 zeolite, and alumina or silica is used as binder. The technology adopts a two-stage reaction device, and a first-stage reactor is carried out at the temperature of 300-550 ℃ without hydrogen and 0.05-1Contacting and reacting the raw material and the catalyst under the conditions of 2MPa and weight hourly space velocity of 0.2-10, carrying out gas-liquid separation on reaction products, and C₅And (3) after the liquid is discharged from the device, fractionating, sending the obtained gasoline fraction into a second-stage reactor, carrying out aromatization reaction under the conditions of 0.05-1.5 MPa, volume space velocity of 20-2000 and bed temperature of 480-650 ℃, and carrying out gas-liquid separation on reaction products to obtain an aromatic hydrocarbon mixture and hydrogen-rich gas.

Chinese patent CN 1212376A discloses a light hydrocarbon non-hydrogenation modified catalyst, a preparation method and application thereof, relating to a C₃～C₁₁The non-hydrogenation catalyst for modifying the light hydrocarbon mixture comprises 0.1-5.0 mass% of mixed rare earth oxide or antimony oxide and 95.0-99.1 mass% of a carrier, wherein the carrier consists of 50-80 mass% of HZSM-5 zeolite and 20-50 mass% of gamma-alumina. The catalyst is used for modifying low-octane gasoline to improve the octane number of the gasoline and reduce the content of olefin.

Chinese patent CN 1651141A discloses an aromatization catalyst and a preparation method and application thereof, wherein modified ZSM-5 and a Y-type molecular sieve are used as active components, modified elements are zinc, phosphorus and rare earth metals, the Y-type molecular sieve is REY or high silica Y, and aluminum sol or silica sol is used as a binder to prepare a small-ball catalyst with the diameter of 1.4-2.0 mm through rolling molding. The catalyst is applied to a moving bed reactor, and can realize continuous aromatization reaction of low-octane gasoline or naphtha. The method can continuously and stably obtain the product yield and distribution, but the yield of the dry gas obtained by the reaction is still high, and the device investment is large.

In order to reduce the cracking capability of the ZSM-5 molecular sieve, the gasoline loss is reduced as much as possible, and the improvement of the silica-alumina ratio is an effective modification means.

Chinese patent CN 101269340A discloses a ZSM-5 zeolite catalyst with high silica-alumina ratio and a preparation method thereof. The catalyst is prepared by taking an active pure silicon compound as a silicon source, adding trace aluminum and adopting a hydrothermal synthesis method. The zeolite skeleton has Si/Al ratio over 1000, submicron crystal grain, open pore passage, large specific surface area and high molecular diffusivity.

Chinese patent CN 1046922A discloses a method for improving the silica-alumina ratio of a ZSM-5 molecular sieve. The molecular sieve is a molecular sieve with high silicon-aluminum ratio and high crystallinity, is prepared by pressurized water-pressure heat treatment and acid treatment, and has no or only a small amount of non-framework aluminum in the product.

Chinese patent CN 103480411A discloses a molecular sieve catalyst containing mesoporous ZSM-5 and a preparation method thereof. According to the method, a cheap silicon-aluminum source, potassium salt and an organic template agent are dissolved in water, the system is subjected to heating ultrasonic auxiliary mechanical stirring by utilizing the cavitation action of ultrasonic waves, meanwhile, the salting-out effect of the potassium salt is utilized to generate a structure guiding effect, and finally, the mesoporous ZSM-5-containing molecular sieve with MFI structural property and high silicon-aluminum ratio is synthesized by a hydrothermal method.

Chinese patent CN 101857243A discloses a method for adjusting the surface aperture of a ZSM-5 molecular sieve by surface dealuminization and silicon supplementation, which adopts ammonium fluosilicate solution to carry out dealuminization and silicon supplementation treatment on the surface of the ZSM-5 zeolite molecular sieve to realize the accurate control of the surface aperture. The ZSM-5 zeolite molecular sieve is modified by ammonium fluosilicate, Al in the surface framework of the molecular sieve is isomorphously replaced by Si, and the bond length of Si-O is less than that of Al-O, so that the diameter of the orifice on the surface of the molecular sieve can be reduced, and a silicon-rich ultrathin layer is formed on the surface of the molecular sieve. By fine control of the treatment conditions, the degree of shrinkage of the molecular sieve surface pores can be controlled.

In the prior art, a template agent with high price is needed for directly synthesizing the ZSM-5 molecular sieve with high silica-alumina ratio, the cost is high, the production difficulty is high, the three wastes are discharged highly, and the synthesized ZSM-5 molecular sieve has fine crystal grains (100-300 nm) and poor hydrothermal stability and is difficult to popularize and apply in a catalytic cracking catalyst.

Disclosure of Invention

The MFI structure molecular sieve containing phosphorus and supported metal is used as an active component to prepare a catalyst or an auxiliary agent, so that the yield and the octane number of gasoline can be improved and the olefin content of the gasoline can be effectively reduced in the catalytic cracking reaction of petroleum hydrocarbon.

To achieve the above objectThe present disclosure provides a phosphorus-containing and metal-loaded MFI structure molecular sieve having n (SiO)₂)/n(Al₂O₃) Greater than 100; with P₂O₅The phosphorus content of the molecular sieve is 0.1-5 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-5 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: 0.5-D (Al) -0.8, wherein D (Al) -Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the edge of a crystal face of the molecular sieve crystal grain to the inside H of the crystal face measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the geometric center of the crystal face of the molecular sieve crystal grain to the outside H of the geometric center measured by the TEM-EDS method, wherein H is 10% of the distance from a certain point on the edge of the crystal face to the geometric center of the crystal face; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d ≦ d (m) ≦ 10, where d (m) ═ m (s)/m (c), m(s) represents the supported metal content of the molecular sieve crystal grains measured by TEM-EDS method in any region greater than 100 square nanometers within the distance H inward of the edges of the crystal faces, m (c) represents the supported metal content of the molecular sieve crystal grains measured by TEM-EDS method in any region greater than 100 square nanometers within the distance H outward of the geometric centers of said crystal faces; the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 15-30% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60-80%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100.

Preferably, n (SiO) of the molecular sieve₂)/n(Al₂O₃) Greater than 120; with P₂O₅The phosphorus content of the molecular sieve is 0.1-4 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-3 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: d (Al) is more than or equal to 0.55 and less than or equal to 0.75; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d is more than or equal to 3 and less than or equal to 6 (M); the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 20-25% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is70-75%, and the ratio of B acid amount to L acid amount is 30-80.

Preferably, the load metal is at least one selected from zinc and gallium.

Preferably, the mesopores are molecular sieve pores with the pore diameter of more than 2 nanometers and less than 100 nanometers; the strong acid amount of the molecular sieve is NH in proportion to the total acid amount₃The TPD method, the acid centre of which is NH₃Desorbing the corresponding acid center at the temperature of more than 300 ℃; and the ratio of the acid amount of the B acid to the acid amount of the L acid is measured by adopting a pyridine adsorption infrared acidity method.

The present disclosure also provides a method for preparing an MFI structure molecular sieve containing phosphorus and a supported metal, the method comprising: a. carrying out ammonium exchange treatment on the sodium type MFI structure molecular sieve to obtain an ammonium exchange molecular sieve; wherein the ammonium exchanged molecular sieve has a sodium content of less than 0.2 wt.% based on the total dry basis weight of the ammonium exchanged molecular sieve, calculated as sodium oxide; b. b, dealuminizing the ammonium exchange molecular sieve obtained in the step a in a composite acid dealuminizing agent solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a dealuminized molecular sieve; c. b, carrying out phosphorus modification treatment and loading treatment of loaded metal on the dealuminized molecular sieve obtained in the step b to obtain a modified molecular sieve; d. and c, carrying out hydrothermal roasting treatment on the modified molecular sieve obtained in the step c in a 100% steam atmosphere to obtain the MFI structure molecular sieve containing phosphorus and loaded metal.

Preferably, the step of dealuminizing in step b further comprises: mixing organic acid with the ammonium exchange molecular sieve, and then mixing fluosilicic acid and inorganic acid with the ammonium exchange molecular sieve.

Preferably, the organic acid in step b is at least one selected from the group consisting of ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid, and the inorganic acid is at least one selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid.

Preferably, the organic acid in step b is oxalic acid, and the inorganic acid is hydrochloric acid.

Preferably, the dealumination treatment conditions in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.02-0.5): 0.05-0.5); the treatment temperature is 25-100 ℃, and the treatment time is 0.5-6 hours.

Preferably, the dealumination treatment conditions in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.05-0.3):(0.1-0.3):(0.1-0.3).

Preferably, the phosphorus modification treatment in step c comprises: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate is used to impregnate and/or ion-exchange the molecular sieve.

Preferably, the metal-supporting process in step c includes: dissolving soluble salt containing at least one load metal selected from zinc and gallium in deionized water, adjusting pH value with ammonia water to precipitate the load metal in the form of hydroxide, and mixing the obtained precipitate and molecular sieve uniformly.

Preferably, the conditions of the hydrothermal roasting treatment in step d include: the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

The inventor of the present disclosure unexpectedly found that the MFI structure molecular sieve containing phosphorus and supported metal prepared by dealuminizing the MFI structure molecular sieve by a chemical method, then performing phosphorus modification treatment, supported metal loading treatment and hydrothermal roasting treatment can be used as an active component of a catalyst or an auxiliary agent in a catalytic cracking process.

The MFI structure molecular sieve provided by the disclosure has high silica-alumina ratio and low total acid content, can reduce cracking activity, can inhibit surface non-selective side reactions due to surface silicon-rich, and is beneficial to the isomerization reaction due to rich mesopores, high strong acid center ratio and high B acid/L acid ratio. The surface enriched loading metal can avoid the damage to the acid active center in the pore canal of the molecular sieve, simultaneously strengthen the aromatization performance of the molecular sieve, reduce the olefin content in the gasoline and improve the aromatic hydrocarbon content.

The MFI structure molecular sieve has the characteristics of weak cracking capability and strong aromatization capability, can be used as a catalytic cracking catalytic material, can reduce the olefin content in gasoline, increase the aromatic hydrocarbon content in gasoline and keep the octane number of the gasoline from being reduced while improving the gasoline yield.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The present disclosure provides a phosphorus-containing and metal-loaded MFI structure molecular sieve, n (SiO) of the molecular sieve₂)/n(Al₂O₃) Greater than 100; with P₂O₅The phosphorus content of the molecular sieve is 0.1-5 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-5 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: 0.5-D (Al) -0.8, wherein D (Al) -Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the edge of a crystal face of the molecular sieve crystal grain to the inside H of the crystal face measured by a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the geometric center of the crystal face of the molecular sieve crystal grain to the outside H of the geometric center measured by the TEM-EDS method, wherein H is 10% of the distance from a certain point on the edge of the crystal face to the geometric center of the crystal face; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d ≦ d (m) ≦ 10, where d (m) ═ m (s)/m (c), m(s) represents the supported metal content of the molecular sieve crystal grains measured by TEM-EDS method in any region greater than 100 square nanometers within the distance H inward of the edges of the crystal faces, m (c) represents the supported metal content of the molecular sieve crystal grains measured by TEM-EDS method in any region greater than 100 square nanometers within the distance H outward of the geometric centers of said crystal faces; the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 15-30% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60-80%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100; preferably, n (SiO) of the molecular sieve₂)/n(Al₂O₃) Greater than 120; with P₂O₅The phosphorus content of the molecular sieve is 0.1-4 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-3 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: d (Al) is more than or equal to 0.55 and less than or equal to 0.75; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d is more than or equal to 3 and less than or equal to 6 (M); the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 20-25% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 70-75%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 30-80.

According to the present disclosure, the supported metal refers to a metal supported on a molecular sieve by a supporting manner, and does not include aluminum and alkali metals such as sodium and potassium, and may be zinc and/or gallium, and may also include other metals, and the present disclosure is not limited thereto.

According to the present disclosure, it is well known to those skilled in the art to determine the aluminum content and the supported metal content of the molecular sieve by using a TEM-EDS method, wherein the geometric center is also well known to those skilled in the art and can be calculated according to a formula, which is not repeated in the present disclosure, the geometric center of a general symmetric graph is an intersection point of connecting lines of respective opposite vertices, for example, the geometric center of a hexagonal crystal face of a conventional hexagonal plate-shaped ZSM-5 is at an intersection point of connecting lines of three opposite vertices, the crystal face is one face of a regular crystal grain, and the inward and outward directions are both inward and outward directions on the crystal face.

According to the disclosure, the proportion of the mesoporous volume of the molecular sieve to the total pore volume is measured by a nitrogen adsorption BET pore volume determination method, the mesoporous volume being the pore volume with a pore diameter of more than 2 nanometers and less than 100 nanometers; the strong acid amount of the molecular sieve is NH in proportion to the total acid amount₃The TPD method, the acid centre of which is NH₃Desorbing the corresponding acid center at the temperature of more than 300 ℃; and the ratio of the acid amount of the B acid to the acid amount of the L acid is measured by adopting a pyridine adsorption infrared acidity method.

In light of the present disclosure, the sodium MFI structure molecular sieve is well known to those skilled in the art, and may be obtained by amine-free crystallization or prepared by a template method, wherein the amine-free crystallized molecular sieve does not need to be calcined, the molecular sieve prepared by the template method needs to be dried and then calcined in air, and the silica-alumina ratio of the ZSM-5 molecular sieve is generally less than 100.

Both the organic acid and the inorganic acid in step b are well known to those skilled in the art in light of the present disclosure, and for example, the organic acid may be at least one selected from ethylenediaminetetraacetic acid, oxalic acid, citric acid, and sulfosalicylic acid, preferably oxalic acid; the inorganic acid may be at least one selected from hydrochloric acid, sulfuric acid and nitric acid, and is preferably hydrochloric acid.

The dealumination treatment described in step b is well known to those skilled in the art in light of the present disclosure, but the use of inorganic acids, organic acids and fluorosilicic acids together for dealumination treatment has not been reported. The dealumination treatment can be carried out once or for multiple times, organic acid can be firstly mixed with the ammonium exchange molecular sieve, and then fluosilicic acid and inorganic acid are mixed with the ammonium exchange molecular sieve, namely, the organic acid is firstly added into the ammonium exchange molecular sieve, and then the fluosilicic acid and the inorganic acid are slowly and concurrently added, or the fluosilicic acid is firstly added and then the inorganic acid is added, preferably the fluosilicic acid and the inorganic acid are slowly and concurrently added. The dealumination treatment conditions may be: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.02-0.5): (0.05-0.5): 0.05-0.5), preferably 1: (0.05-0.3): (0.1-0.3): 0.1-0.3); the treatment temperature is 25-100 ℃, and the treatment time is 0.5-6 hours.

The phosphorus modification treatment and the metal-supporting treatment are well known to those skilled in the art in light of the present disclosure, and the phosphorus modification treatment in step c may include: impregnating and/or ion-exchanging the molecular sieve with at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate; the loading treatment of the loaded metal in step c may include: dissolving soluble salt containing at least one load metal selected from zinc and gallium in deionized water, adjusting pH value with ammonia water to precipitate the load metal in the form of hydroxide, and mixing the obtained precipitate and molecular sieve uniformly.

In light of the present disclosure, hydrothermal calcination treatment is well known to those skilled in the art, and the hydrothermal calcination treatment conditions in step d may be: the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.

The washing described in this disclosure is well known to those skilled in the art and can be done in the following manner: and (3) leaching the filtered molecular sieve by using water with the temperature of 30-60 ℃ which is 5-10 times that of the filtered molecular sieve.

The present disclosure is further illustrated by the following examples, which are not intended to be limiting and the instruments and reagents used in the examples of the present disclosure are those commonly used by those skilled in the art unless otherwise specified.

The influence of the molecular sieve on the yield and octane number of gasoline in the catalytic cracking of petroleum hydrocarbon is evaluated by heavy oil micro-reaction. Preparing a catalytic cracking auxiliary agent by taking a molecular sieve as an active component, wherein the content of the molecular sieve is 50 percent, and the balance is kaolin and an alumina carrier, aging the prepared auxiliary agent sample at 800 ℃ under 100 percent of water vapor for 17 hours on a fixed bed aging device, then using a catalytic cracking balancing agent (from catalyst Qilu division, a brand DVI catalyst) without a shape-selective molecular sieve as a basic catalyst, and mixing the basic catalyst and the auxiliary agent according to a ratio of 95: 5, and then evaluating on a catalytic cracking fluidized bed by micro-reaction, wherein the raw material oil is mixed slag VGO, and the evaluation conditions are that the reaction temperature is 500 ℃, the regeneration temperature is 600 ℃, and the agent-oil ratio is 5.92. The blank was evaluated as 100% catalytic cracking balance.

The micro-inversion conversion of the present disclosure is determined using the ASTM D5154-2010 standard method, and the octane number of the micro-inversion product is determined using the RIPP 85-90 method.

The crystallinity of the present disclosure is determined using the standard method of ASTM D5758-2001(2011) e 1.

N (SiO) of the present disclosure₂)/n(Al₂O₃) Namely, the silicon-aluminum ratio is calculated by the contents of silicon oxide and aluminum oxide, and the contents of the silicon oxide and the aluminum oxide are measured by the GB/T30905-2014 standard method.

The phosphorus content of the composition is determined by a GB/T30905-.

See methods for solid catalyst investigation, petrochemical, 29(3), 2000: 227.

total specific surface area (S) of the present disclosure_BET) The measurement methods of the mesoporous volume and the total pore volume are as follows:

the measurement was carried out by using AS-3, AS-6 static nitrogen adsorption apparatus manufactured by Quantachrome instruments.

The instrument parameters are as follows: the sample was placed in a sample handling system and evacuated to 1.33X 10 at 300 deg.C^-2Pa, keeping the temperature and the pressure for 4h, and purifying the sample. Testing the purified samples at different specific pressures P/P at a liquid nitrogen temperature of-196 DEG C₀The adsorption quantity and the desorption quantity of the nitrogen under the condition are obtained to obtain N₂Adsorption-desorption isotherm curve. Then, the total specific surface area is calculated by utilizing a two-parameter BET formula, and the specific pressure P/P is taken₀The adsorption capacity of 0.98 or less is the total pore volume of the sample, the pore size distribution of the mesoporous portion is calculated by the BJH formula, and the mesoporous pore volume (2 to 100 nm) is calculated by the integration method.

The method for measuring the amount of the B acid and the amount of the L acid is as follows:

an FTS3000 Fourier Infrared spectrometer manufactured by BIO-RAD of America was used.

And (3) testing conditions are as follows: pressing the sample into tablet, sealing in an in-situ cell of an infrared spectrometer, and vacuumizing to 10 deg.C at 350 deg.C^-3Pa, keeping for 1h to enable gas molecules on the surface of the sample to be desorbed completely, and cooling to room temperature. Introducing pyridine vapor with pressure of 2.67Pa into the in-situ tank, balancing for 30min, heating to 200 deg.C, and vacuumizing to 10 deg.C^-3Pa, keeping for 30min, cooling to room temperature at 1400-1700cm^-1Scanning in wave number range, and recording infrared spectrogram of pyridine adsorption at 200 ℃. Then the sample in the infrared absorption cell is moved to a heat treatment area, the temperature is raised to 350 ℃, and the vacuum is pumped to 10 DEG^-3Pa, keeping for 30min, cooling to room temperature, and recording the infrared spectrogram of pyridine adsorption at 350 ℃. And automatically integrating by an instrument to obtain the acid content of the B acid and the acid content of the L acid.

The method for measuring the total acid amount and the strong acid amount of the present disclosure is as follows:

an Autochem II 2920 programmed temperature desorption instrument of Michman, USA, is adopted.

And (3) testing conditions are as follows: weighing 0.2g of a sample to be detected, putting the sample into a sample tube, putting the sample tube into a thermal conductivity cell heating furnace, taking He gas as carrier gas (50mL/min), heating the sample tube to 600 ℃ at the speed of 20 ℃/min, and purging the sample tube for 60min to remove impurities adsorbed on the surface of the catalyst. Then cooling to 100 ℃, keeping the temperature for 30min, and switching to NH₃-He mixed gas (10.02% NH)₃+ 89.98% He) for 30min, and then continuing to purge with He gas for 90min until the baseline is stable, so as to desorb the physically adsorbed ammonia gas. And (4) heating to 600 ℃ at the heating rate of 10 ℃/min for desorption, keeping for 30min, and finishing desorption. Detecting gas component change by TCD detector, automatically integrating by instrument to obtain total acid amount and strong acid amount, wherein acid center of strong acid is NH₃The desorption temperature is higher than 300 ℃ of the corresponding acid center.

The RIPP standard method disclosed in the disclosure can be found in petrochemical analysis methods, edition such as Yangcui, 1990 edition.

The D value is calculated as follows: selecting a crystal grain and a certain crystal face of the crystal grain in a transmission electron mirror to form a polygon, wherein the polygon has a geometric center, an edge and a 10% distance H (different edge points and different H values) from the geometric center to the edge, any one of regions in the inward H distance of the edge of the crystal face which is more than 100 square nanometers and any one of regions in the outward H distance of the geometric center of the crystal face which is more than 100 square nanometers are respectively selected to determine the aluminum content, namely Al (S1) and Al (C1), calculating D (Al)1 ═ Al (S1)/Al (C1), respectively selecting different crystal grains to determine for 5 times, and calculating the average value which is D (Al), and the determination method of D (M) is similar to D (Al).

Example 1

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 20g of oxalic acid while stirring, then adding 200g of hydrochloric acid (with the mass fraction of 10%) and 167g of fluosilicic acid (with the mass fraction of 3%) in a concurrent flow manner, and adding for 30 min; heating to 65 ℃, stirring for 1h at constant temperature, filtering, washing with water until the filtrate is neutral, adding water into a filter cake, and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 2.4gH₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂Dissolving O in deionized water, adding ammonia water to adjust the pH value to 6, then adding the mixture into the molecular sieve slurry, uniformly mixing, drying, and roasting at 550 ℃ in a 100% water vapor atmosphere for 2 hours. The molecular sieve A is obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are listed in Table 1.

Comparative example 1

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 20g of oxalic acid while stirring, then adding 200g of hydrochloric acid (with the mass fraction of 10%) and 167g of fluosilicic acid (with the mass fraction of 3%) in a concurrent flow manner, and adding for 30 min; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake and pulping to obtain the components with the solid content of 40 weight percentSieving the slurry, adding 2.4gH₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA1 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 2

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, and adding 48g of oxalic acid while stirring; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA2 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 3

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, and adding 390g of hydrochloric acid (the mass fraction is 10 percent) while stirring; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA3 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 4

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless Synthesis, n)(SiO₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; 100g (dry basis) of the molecular sieve is taken and added with water to prepare molecular sieve slurry with the solid content of 10 weight percent, 670g (mass fraction of 3 percent) of fluosilicic acid is added during stirring, and the adding time is 30 min; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA4 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 5

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 20g of oxalic acid while stirring, then adding 200g of hydrochloric acid (the mass fraction is 10 percent), and adding for 30 min; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA5 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 6

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; adding water into 100g (dry basis) of the molecular sieve to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 20g of oxalic acid while stirring, and slowly adding 334g of fluosilicic acid (the mass fraction is 3 percent) for 30 min;heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA6 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 7

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, and adding 200g of hydrochloric acid (the mass fraction is 10 percent) and 334g of fluosilicic acid (the mass fraction is 3 percent) in a concurrent flow manner for 30min under stirring; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.4g H₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Molecular sieve DA7 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 8

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; adding water into 100g (dry basis) of the molecular sieve to prepare molecular sieve slurry with the solid content of 10 weight percent, slowly adding 1332g (mass fraction of 3%) of fluosilicic acid under stirring for 30 min; heating to 65 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 1.5gH₃PO₄(concentration 85% by weight) and 6.6gZn (NO)₃)₂·6H₂And O, uniformly mixing, soaking, drying and roasting at 550 ℃ for 2 hours. Obtaining molecular sieve DAThe physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Example 2

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 40g of citric acid while stirring, then adding 100g of sulfuric acid (with the mass fraction of 10%) and 500g of fluosilicic acid (with the mass fraction of 3%) in a concurrent flow manner, and adding for 30 min; heating to 45 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 2.0gH₃PO₄(concentration 85% by weight) and 3.6 g Ga₂(SO₄)₃·16H₂Dissolving O in deionized water, adding ammonia water to adjust the pH value to 4, then adding the mixture into the molecular sieve slurry, uniformly mixing, drying, and roasting at 550 ℃ in a 100% water vapor atmosphere for 2 hours. The molecular sieve B is obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are listed in Table 1.

Comparative example 9

ZSM-5 molecular sieve (produced by catalyst Qilu division, Amineless synthesis, n (SiO)₂)/n(Al₂O₃) 27) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; taking 100g (dry basis) of the molecular sieve, adding water to prepare molecular sieve slurry with the solid content of 10 weight percent, adding 40g of citric acid while stirring, then adding 100g of sulfuric acid (with the mass fraction of 10%) and 500g of fluosilicic acid (with the mass fraction of 3%) in a concurrent flow manner, and adding for 30 min; heating to 45 ℃, stirring for 1h at constant temperature, filtering and washing until the filtrate is neutral; adding water into the filter cake, pulping to obtain molecular sieve slurry with solid content of 40 wt%, adding 2.0gH₃PO₄(concentration: 85 wt.%), mixing, immersing, baking, and calcining at 550 deg.C for 2 hr. Molecular sieve DB1 was obtained, and the physicochemical properties, the gasoline yield and the octane number data of the micro-reverse evaluation are shown in Table 1.

Comparative example 10

This comparative example illustrates phosphorus modification treatment using a direct synthesis of a high silica to alumina ratio molecular sieve.

ZSM-5 molecular sieve (catalyst produced by Jianchangdian company, and synthesized by amine method, n (SiO)₂)/n(Al₂O₃) 210) with NH₄Cl solution exchange washing to Na₂The content of O is lower than 0.2 weight percent, and a filter cake is obtained by filtration; adding water into 100g (dry basis) of the molecular sieve and pulping to obtain molecular sieve slurry with the solid content of 40 weight percent; 1.6gH₃PO₄(concentration 85%) and 6.6gZn (NO)₃)₂·6H₂Dissolving O in deionized water, adding ammonia water to adjust the pH value to 6, then adding the mixture into the molecular sieve slurry, uniformly mixing, drying, and roasting at 550 ℃ in a 100% water vapor atmosphere for 2 hours to obtain the molecular sieve DA 9. Physicochemical properties, micro-reverse evaluation gasoline yield and octane number data are listed in table 1.

As can be seen from the data in Table 1, the single organic acid oxalic acid dealumination (DA2) and the single inorganic acid hydrochloric acid dealumination (DA3) as well as the two acids of organic acid oxalic acid and inorganic acid hydrochloric acid composite (DA5) can not effectively remove Al in the ZSM-5 molecular sieve, the silica-alumina ratio is basically unchanged, and a good dealumination effect can be obtained only after the fluosilicic acid is used. When fluosilicic acid is used alone for dealumination (DA4), the ZSM-5 molecular sieve with high silica-alumina ratio can be obtained, but the mesopores are less, the proportion of strong acid in the total acid is lower, and the proportion of B acid/L acid is lower. The fluosilicic acid and organic acid composite oxalic acid dealumination (DA6) can not obtain higher mesopore volume. The composite inorganic acid fluosilicate dealumination (DA7) increases the volume of mesopores, but the proportion of strong acid in the total acid and the proportion of B acid/L acid are not as high as those of the molecular sieve provided by the present disclosure. The ZSM-5 molecular sieve (DA8) with higher silica-alumina ratio can be obtained by simply increasing the dosage of the fluosilicic acid, but the loss of the crystallinity of the molecular sieve is serious, and the mesoporous ratio and the acid distribution are not improved. The composite acid system is used, and under the synergistic effect of the three acids, the silicon-aluminum ratio of the molecular sieve can be effectively increased on the premise of ensuring the structural integrity of the molecular sieve, the aluminum distribution is adjusted, the mesoporous proportion is increased, and the acid distribution is improved. The loaded metal in the molecular sieve prepared by the method is enriched on the surface of the molecular sieve, and the molecular sieve prepared by the method can effectively adjust the gasoline composition, reduce the olefin content and improve the aromatic hydrocarbon content while keeping the gasoline yield from the micro-reverse evaluation of the gasoline yield and the octane number data, and the gasoline octane number is not reduced.

TABLE 1

Claims

1. Phosphorus-containing and metal-loaded MFI structure molecular sieve, n (SiO) of the molecular sieve₂)/n(Al₂O₃) Greater than 100; with P₂O₅The phosphorus content of the molecular sieve is 0.1-5 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-5 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: d (Al) is more than or equal to 0.5 and less than or equal to 0.8, wherein D (Al) = Al (S)/Al (C), Al (S) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the edge of a crystal face of the molecular sieve crystal grain to the inner H by adopting a TEM-EDS method, Al (C) represents the aluminum content of a region which is arbitrarily more than 100 square nanometers in the distance from the geometric center of the crystal face of the molecular sieve crystal grain to the outer H by adopting the TEM-EDS method, wherein H is 10 percent of the distance from a certain point on the edge of the crystal face to the geometric center of the crystal face; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d is more than or equal to 2 and less than or equal to 10, wherein D (M) = M (S)/M (C), M (S) represents the content of the load metal in any area more than 100 square nanometers within the inward H distance of the edges of the crystal faces of the molecular sieve crystal grains measured by a TEM-EDS method, and M (C) represents the content of the load metal in any area more than 100 square nanometers within the outward H distance of the geometric centers of the crystal faces of the molecular sieve crystal grains measured by a TEM-EDS method; the proportion of the mesoporous volume of the molecular sieve in the total pore volume is 15-30% by volume, and the mesopores are molecular sieve pore passages with the pore diameter of more than 2 nanometers and less than 100 nanometers; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 60-80%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 20-100.

2. The MFI structure molecular sieve of claim 1, wherein n (SiO) of the molecular sieve₂)/n(Al₂O₃) Greater than 120; with P₂O₅The phosphorus content of the molecular sieve is 0.1-4 wt% based on the dry weight of the molecular sieve; the content of the supported metal of the molecular sieve is 0.5-3 wt% calculated by the oxide of the supported metal and based on the dry weight of the molecular sieve; the molecular sieve has an Al distribution parameter D (Al) satisfying: d (Al) is more than or equal to 0.55 and less than or equal to 0.75; the molecular sieve has a supported metal distribution parameter D (M) satisfying: d is more than or equal to 3 and less than or equal to 6 (M); the proportion of the mesoporous volume of the molecular sieve to the total pore volume is 20-25% by volume; the ratio of the strong acid amount of the molecular sieve to the total acid amount is 70-75%, and the ratio of the acid amount of the B acid to the acid amount of the L acid is 30-80.

3. The MFI structure molecular sieve of claim 1, wherein the supported metal is at least one selected from zinc and gallium.

4. The MFI structure molecular sieve of claim 1, wherein the ratio of the strong acid content to the total acid content of the molecular sieve is NH₃The TPD method, the acid centre of which is NH₃Desorbing the corresponding acid center at the temperature of more than 300 ℃; and the ratio of the acid amount of the B acid to the acid amount of the L acid is measured by adopting a pyridine adsorption infrared acidity method.

5. A process for the preparation of a phosphorus-containing and metal-loaded MFI structure molecular sieve as claimed in any one of claims 1 to 4, which process comprises:

a. carrying out ammonium exchange treatment on the sodium type MFI structure molecular sieve to obtain an ammonium exchange molecular sieve; wherein the ammonium exchanged molecular sieve has a sodium content of less than 0.2 wt.%, based on sodium oxide and based on total dry basis weight of the ammonium exchanged molecular sieve;

b. b, dealuminizing the ammonium exchange molecular sieve obtained in the step a in a composite acid dealuminizing agent solution consisting of fluosilicic acid, organic acid and inorganic acid, and filtering and washing to obtain a dealuminized molecular sieve, wherein the inorganic acid is at least one selected from hydrochloric acid, sulfuric acid and nitric acid;

c. b, carrying out phosphorus modification treatment and loading treatment of loaded metal on the dealuminized molecular sieve obtained in the step b to obtain a modified molecular sieve;

d. and c, carrying out hydrothermal roasting treatment on the modified molecular sieve obtained in the step c in a 100% steam atmosphere to obtain the MFI structure molecular sieve containing phosphorus and loaded metal.

6. The method of claim 5, wherein the step of dealuminating in step b further comprises: mixing organic acid with the ammonium exchange molecular sieve, and then mixing fluosilicic acid and inorganic acid with the ammonium exchange molecular sieve.

7. The production method according to claim 5, wherein the organic acid in step b is at least one selected from the group consisting of ethylenediaminetetraacetic acid, oxalic acid, citric acid and sulfosalicylic acid.

8. The method according to claim 5, wherein the organic acid in step b is oxalic acid and the inorganic acid is hydrochloric acid.

9. The production method according to claim 5, wherein the conditions of the dealumination treatment in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.02-0.5): 0.05-0.5); the treatment temperature is 25-100 ℃, and the treatment time is 0.5-6 hours.

10. The production method according to claim 5, wherein the conditions of the dealumination treatment in step b include: the weight ratio of the molecular sieve, the fluosilicic acid, the organic acid and the inorganic acid is 1: (0.05-0.3):(0.1-0.3):(0.1-0.3).

11. The production method according to claim 5, wherein the phosphorus modification treatment in step c comprises: at least one phosphorus-containing compound selected from phosphoric acid, ammonium hydrogen phosphate, ammonium dihydrogen phosphate and ammonium phosphate is used to impregnate and/or ion-exchange the molecular sieve.

12. The production method according to claim 5, wherein the supporting treatment of the supported metal in step c includes: dissolving soluble salt containing at least one load metal selected from zinc and gallium in deionized water, adjusting pH value with ammonia water to precipitate the load metal in the form of hydroxide, and mixing the obtained precipitate and molecular sieve uniformly.

13. The preparation method according to claim 5, wherein the conditions of the hydrothermal roasting treatment in step d include: the roasting temperature is 400-800 ℃, and the roasting time is 0.5-8 hours.