Supported deoxidation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of chemical oxygen-containing tail gas deoxidation, and discloses a supported deoxidation catalyst as well as a preparation method and application thereof. The supported deoxidation catalyst comprises a carrier, an active component and an optional auxiliary agent, wherein the active component and the optional auxiliary agent are supported on the carrier; the carrier is a molecular sieve, the grain size of the molecular sieve is 50-300nm, and the specific surface area of the molecular sieve is 350-450m < 2 > / g; the molar ratio of silicon to aluminum is (10-80): 1; the active component is noble metal; the auxiliary agent is alkali metal and / or alkaline earth metal. According to the supported deoxidation catalyst disclosed by the invention, the molecular sieve with a hierarchical pore structure is used as the carrier, and the abundant pore structure of the molecular sieve promotes dispersion of the active component in the process of being supported on the carrier and also provides a plurality of falling sites for the active center, so that the catalyst with high metal dispersity can be further prepared; the possibility is provided for exposure of more active sites.

Description

Technical Field

[0001] The present invention relates to the field of deoxidation of oxygen-containing tail gas in chemical industry, and in particular to a supported deoxidation catalyst and a preparation method and application thereof. Background Art

[0002] Chemical safety is a crucial issue affecting my country's national economy and people's livelihood. Among the 18 hazardous processes under key regulatory scrutiny, oxidation processes play a crucial role in the production of many bulk chemicals. Oxidants such as oxygen are essential for these processes, but incomplete chemical reactions often result in the production of oxygen-containing organic gases. SH 3009-2013, "Petrochemical Flammable Gas Emission System Design Specification," stipulates that "flammable gases with an oxygen content greater than 2% (v%)" should not be discharged into the plant's overall flammable gas emission system. Therefore, the treatment of this exhaust gas has become a key concern for the industry.

[0003] The use of catalytic methods to treat this tail gas has the advantages of strong operability and simple process, and has broad application prospects in the field of deoxygenation of oxygen-containing organic gases in chemical processes. The core of the catalytic deoxygenation process lies in the design of the deoxygenation catalyst. CN100579653C proposes a deoxygenation catalyst and its preparation method and application. The catalyst contains oxides of metal elements such as Zn, Ni, and Au, and uses Al2O3 as a binder. The preparation process adopts co-precipitation and other methods. It can deoxygenate oxygen-containing propane / propylene mixed gases with an oxygen content of about 15vol.% to an oxygen content of <1vol.% at 200°C. CN113244931B) discloses a catalyst and a method for catalytic oxidation deoxygenation of unsaturated hydrocarbon gases. The catalyst disclosed in the method comprises a carrier and an active component supported on the carrier, a first auxiliary component, and a second auxiliary component. The first auxiliary component comprises one or more of a rare earth metal element, a Group IVB metal element, and a Group VIII metal element, and the second auxiliary component comprises one or more of an alkali metal element and an alkaline earth metal element. The deoxygenation catalyst prepared by this method can directly react organic hydrocarbon gases with oxygen to achieve the purpose of deoxygenation. Queen's University, Northern Ireland (Applied Catalysis A: General, 2011, 391, 187-193) reported an Ag-based catalyst for deoxygenating oxygen-containing ethylene gas. The catalyst can achieve hydrodeoxygenation of oxygen-containing ethylene gas at temperatures below 100°C, while maintaining a low level of hydrogenation selectivity for gases such as ethylene. However, the catalyst loses activity within 20 hours.

[0004] The above method and similar methods in the prior art can achieve tail gas deoxidation under certain working conditions. However, they have problems such as high active component dosage, poor dispersity, and difficulty in fully exerting the reaction activity of noble metals. Achieving high TOF of deoxidation catalysts is always a common goal pursued by researchers in academia and industry. SUMMARY

[0005] The present application aims to overcome the problems of high active component dosage, poor dispersity, and difficulty in fully exerting the reaction activity of noble metals in the prior art deoxidation catalysts, and provides a supported deoxidation catalyst, a preparation method and application thereof. The supported deoxidation catalyst has excellent reaction effect in processes such as hydrogen deoxidation of HPPO process propylene oxide tail gas and hydrogen deoxidation of hydrogen peroxide process epichlorohydrin tail gas.

[0006] To achieve the above-mentioned purpose, the present application provides a supported deoxidation catalyst in one aspect, which comprises a carrier and an active component and an optional adjuvant supported on the carrier.

[0007] The carrier is a molecular sieve, the grain size of the molecular sieve is 50-300 nm, the specific surface area is 350-450 m 2 / g, and the molar ratio of silicon to aluminum is 10-80:1.

[0008] The active component is a noble metal.

[0009] The adjuvant is an alkali metal and / or an alkaline earth metal.

[0010] Preferably, the noble metal is Pd and / or Pt.

[0011] Preferably, the alkali metal is selected from one or more of Li, Na and K.

[0012] Preferably, the alkaline earth metal is selected from one or more of Mg, Ca and Ba.

[0013] Preferably, in the molecular sieve, the molar ratio of silicon to aluminum is 10-60:1.

[0014] Preferably, the supported deoxidation catalyst contains 0.1-1wt% of the active component.

[0015] Preferably, when the supported deoxidation catalyst contains an adjuvant, the supported deoxidation catalyst contains 0.5-5wt% of the adjuvant.

[0016] The second aspect of the present application provides a method for preparing the above-mentioned supported deoxidation catalyst, which comprises the following steps:

[0017] (1) mixing a silicon source, an aluminum source, a template, an alkali, a seed crystal, and water to obtain a raw material mixture;

[0018] (2) allowing the raw material mixture to stand, crystallize, and calcine in sequence to obtain a molecular sieve;

[0019] (3) impregnating the active component precursor and the optional auxiliary agent precursor onto the molecular sieve obtained in step (2), followed by drying and calcining;

[0020] Wherein, the template is tetraethylammonium hydroxide and / or tetraethylammonium bromide, and the molar ratio of the silicon source, aluminum source, template, alkali and water is 0.1-250:0.1-18:0.3-42:1:5-625, the silicon source is calculated as SiO2, and the aluminum source is calculated as Al2O3;

[0021] The weight ratio of the total amount of the silicon source and the aluminum source to the amount of the seed crystal is 100:0.5-10;

[0022] The active component precursor is a noble metal salt; the auxiliary agent precursor is an alkali metal salt and / or an alkaline earth metal salt.

[0023] Preferably, in step (1), the molar ratio of the silicon source, the aluminum source, the template, the base and the water is 0.2-200:0.15-15:0.4-40:1:7-623, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3;

[0024] Preferably, the aluminum source is selected from one or more of sodium metaaluminate, aluminum hydroxide and pseudo-boehmite;

[0025] Preferably, the silicon source is selected from one or more of silica gel, attapulgite and white carbon black;

[0026] Preferably, the base is selected from one or more of sodium hydroxide, potassium hydroxide and sodium carbonate.

[0027] Preferably, in step (2), the standing time is 8-12 hours.

[0028] Preferably, in step (2), the crystallization conditions include: temperature of 160-190° C. and time of 30-180 min.

[0029] Preferably, in step (2), the calcination conditions include: a temperature of 500-600° C. and a time of 1-10 h.

[0030] Preferably, the noble metal salt is selected from palladium-containing compounds and / or platinum-containing compounds;

[0031] Preferably, the alkali metal salt is selected from one or more of lithium salt, sodium salt and potassium salt;

[0032] Preferably, the alkaline earth metal salt is selected from one or more of magnesium salt, calcium salt and barium salt.

[0033] Preferably, in step (3), the calcination conditions include: temperature of 350-700℃, time of 1-10h.

[0034] The third aspect of the present application provides a method for olefin deoxidation, which comprises: subjecting a raw gas containing propylene and oxygen to deoxidation reaction with the supported deoxidation catalyst according to any one of claims 1-4.

[0035] Preferably, the content of oxygen in the raw gas is 1-5% by volume.

[0036] Preferably, the deoxidation reaction conditions include: space velocity of 1000-10000h -1 , temperature of 200-250℃, pressure of 0.2-1MPa.

[0037] The supported deoxidation catalyst of the present application uses a molecular sieve with a multi-level pore structure as the carrier, the abundant pore structure of the molecular sieve promotes the dispersion of the active component during the loading process, and also provides many sites for the active centers, which makes it possible to further prepare a catalyst with high metal dispersion, and provides the possibility for the exposure of more active sites. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the XRD pattern of the molecular sieve prepared in Example 1. DETAILED DESCRIPTION

[0039] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0040] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The endpoints of the ranges of values and the values thereof can be combined with other endpoints to form new ranges and new values, which are also contemplated as disclosed herein.

[0041] The first aspect of the present application provides a supported deoxidation catalyst, which comprises a carrier, and an active component and an optional adjuvant supported on the carrier.

[0042] The carrier is a molecular sieve with a crystal size of 50-300 nm and a specific surface area of ​​350-450 m 2 / g; silicon-aluminum molar ratio is 10-80:1;

[0043] The active component is a noble metal;

[0044] The auxiliary agent is an alkali metal and / or an alkaline earth metal.

[0045] The molecular sieve described in the present invention has an open structure and a multi-level pore structure. Its pores are not blocked and are unobstructed and open. In addition to the microporous structure, the molecular sieve also has a certain degree of mesoporous structure, which enables it to have a higher diffusion rate during the deoxygenation reaction, can reduce coking and carbon deposition during the reaction process, and improve the catalyst life.

[0046] In some preferred embodiments, the molecular sieve of the present invention has a silicon to aluminum molar ratio of 10-60:1.

[0047] In the present invention, the noble metal is Pd and / or Pt.

[0048] More preferably, the alkali metal is selected from one or more of Li, Na and K.

[0049] Preferably, the alkaline earth metal is selected from one or more of Mg, Ca and Ba.

[0050] In the present invention, the supported deoxidation catalyst contains 0.1-1 wt% of active components.

[0051] In a specific embodiment, the content of the active component in the supported deoxygenation catalyst may be 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt% or 1 wt%.

[0052] Preferably, when the supported deoxygenation catalyst contains an auxiliary agent, the supported deoxygenation catalyst contains 0.5-5 wt% of the auxiliary agent.

[0053] A second aspect of the present invention provides a method for preparing the above-mentioned supported deoxygenation catalyst, the method comprising the following steps:

[0054] (1) mixing a silicon source, an aluminum source, a template, an alkali, a seed crystal, and water to obtain a raw material mixture;

[0055] (2) allowing the raw material mixture to stand, crystallize, and calcine in sequence to obtain a molecular sieve;

[0056] (3) impregnating the active component precursor and the optional auxiliary agent precursor onto the molecular sieve obtained in step (2), followed by drying and calcining;

[0057] The molar ratio of the use amount of the silicon source, the aluminum source, the template agent, the alkali and water is 0.1-250:0.1-18:0.3-42:1:5-625, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3;

[0058] The weight ratio of the total use amount of the silicon source and the aluminum source to the use amount of the seed crystal is 100:0.5-10;

[0059] The active component precursor is a noble metal salt, and the auxiliary agent precursor is an alkali metal salt and / or an alkaline earth metal salt.

[0060] In the method, a specific template agent is required to prepare the molecular sieve with the aforementioned characteristics, and therefore, the template agent is preferably tetraethylammonium hydroxide and / or tetraethylammonium bromide.

[0061] In the method, in step (1), the molar ratio of the use amount of the silicon source, the aluminum source, the template agent, the alkali and water is 0.1-250:0.1-18:0.3-42:1:5-625, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3, and the molar ratio of the components in the present application is controlled within the range, so that the molecular sieve with high crystallinity, appropriate crystal size, specific surface area and molar ratio of silicon to aluminum can be prepared.

[0062] In the method, by reasonably controlling the ratio of the raw materials, the nucleation rate and the crystal growth rate of the molecular sieve can be improved, so that the preparation time of the molecular sieve is shortened, the energy consumption is reduced, the use amount of water is reduced, the water resource is saved, and the wastewater discharge is reduced.

[0063] Specifically, on the one hand, the concentration of the raw material mixture is increased by reducing the use amount of water, so that the nucleation rate of the molecular sieve is increased; on the other hand, on the basis of reducing the use amount of water, the alkalinity of the raw material mixture is controlled within an appropriate range by controlling the use amount of the alkali, and the concentration of the template agent is increased within an appropriate range by controlling the use amount of the template agent, so that the crystal growth rate is increased.

[0064] In addition, the use amount of water in the present application is small, the raw material mixture is a gel, and by controlling the ratio of the raw materials within the range of the present application, the gel concentration of the molecular sieve can be maximally increased, and the appropriate water to silicon ratio for the crystal growth of the molecular sieve is ensured, so that the gel ratio is within the synthesis phase region, and the molecular sieve with complete crystallization can be prepared.

[0065] In the method, in order to further promote the crystal growth of the molecular sieve, a seed crystal is further added in the preparation process, and the seed crystal is preferably a Beta molecular sieve which is commonly purchased on the market.

[0066] In a specific embodiment of step (1), the weight ratio of the total amount of the silicon source and the aluminum source to the amount of the seed crystal can be 100:0.5, 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9 or 100:10.

[0067] Further preferably, in step (1), the molar ratio of the amounts of the silicon source (calculated as SiO2), the aluminum source (calculated as Al2O3), the template agent, the base and water is 0.2-200:0.15-15:0.4-40:1:7-623.

[0068] Preferably, the aluminum source can be a routine selection in the art, and in a specific embodiment, the aluminum source is selected from one or more than two of sodium metaaluminate, aluminum hydroxide and pseudoboehmite.

[0069] Preferably, the silicon source can be a routine selection in the art, and in a specific embodiment, the silicon source is selected from one or more than two of silica gel, attapulgite and white carbon black.

[0070] Preferably, the base can be a routine selection in the art, and in a specific embodiment, the base is selected from one or more than two of sodium hydroxide, potassium hydroxide and sodium carbonate.

[0071] In a preferred embodiment, the silicon source, the aluminum source, the template agent and the seed crystal can be ground uniformly before mixing of the raw materials.

[0072] In step (1), the silicon source, the aluminum source, the template agent, the base, the seed crystal and water can be mixed in no particular order as long as they can be mixed uniformly.

[0073] In a preferred embodiment, the template agent and water are mixed first to obtain a template agent solution, then the silicon source and the aluminum source are mixed, and then the seed crystal and the base are added for mixing.

[0074] In step (2) of the present application, the raw material mixture is allowed to stand for a specific period of time before crystallization of the raw material mixture, which can allow the mixed materials to be aged and pre-reacted sufficiently.

[0075] In a preferred case of the present application, in order to ensure sufficient standing, in step (2), the standing time is 8-12 h, and can be specifically 8 h, 9 h, 10 h, 11 h or 12 h.

[0076] In a preferred case of step (2) of the present application, the crystallization conditions include a temperature of 160-190℃ and a time of 30-180 min.

[0077] In a specific embodiment of step (2), the temperature of the crystallization can be 160°C, 170°C, 180°C or 190°C, and the time of the crystallization can be 30 min, 60 min, 90 min, 120 min, 150 min or 180 min.

[0078] In a specific embodiment of the present application, after the crystallization in step (2) is completed, the crystallized product is washed, centrifuged, dried and then calcined.

[0079] In the present application, there is no special requirement for the drying operation in step (2), and the water can be removed. In a specific embodiment, the temperature of the drying in step (2) is 90-110°C.

[0080] Preferably, in step (2), the calcination conditions include a temperature of 500-600°C and a time of 1-10 h.

[0081] In a specific embodiment of step (2), the temperature of the calcination can be 500°C, 525°C, 550°C, 575°C or 600°C, and the time of the calcination can be 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0082] In step (2) of the present application, after the calcination, the organic molecules such as the template agent do not block the pores of the molecular sieve, and thus the obtained molecular sieve has an open structure, i.e., the pores of the molecular sieve are not blocked and are open.

[0083] In the method of the present application, the noble metal salt is selected from a palladium-containing compound and / or a platinum-containing compound.

[0084] In the present application, there is no special requirement for the selection of the palladium-containing compound, and it can be a conventional selection in the art. In a specific embodiment, the palladium-containing compound is selected from one or more than two of palladium nitrate, palladium chlorate, palladium chloride and palladium acetate.

[0085] In the present application, there is no special requirement for the selection of the platinum-containing compound, and it can be a conventional selection in the art. In a specific embodiment, the platinum-containing compound is selected from one or more than two of platinum nitrate, platinum chlorate, platinum chloride and platinum acetate.

[0086] Preferably, the alkali metal salt is selected from one or more than two of a lithium salt, a sodium salt and a potassium salt.

[0087] In the present application, there is no special requirement for the selection of the lithium salt, and it can be a conventional selection in the art. In a specific embodiment, the lithium salt is selected from one or more than two of lithium nitrate, lithium sulfate and lithium chloride.

[0088] In the present application, the selection of the sodium salt is not particularly limited, and can be a conventional selection in the art. In a specific embodiment, the sodium salt is selected from one or more of sodium nitrate, sodium sulfate, and sodium chloride.

[0089] In the present application, the selection of the potassium salt is not particularly limited, and can be a conventional selection in the art. In a specific embodiment, the potassium salt is selected from one or more of potassium nitrate, potassium sulfate, and potassium chloride.

[0090] Preferably, the alkaline earth metal salt is selected from one or more of a magnesium salt, a calcium salt, and a barium salt.

[0091] In the present application, the selection of the magnesium salt is not particularly limited, and can be a conventional selection in the art. In a specific embodiment, the magnesium salt is selected from one or more of magnesium nitrate, magnesium sulfate, and magnesium chloride.

[0092] In the present application, the selection of the calcium salt is not particularly limited, and can be a conventional selection in the art. In a specific embodiment, the calcium salt is selected from calcium nitrate and / or calcium chloride.

[0093] In the present application, the selection of the barium salt is not particularly limited, and can be a conventional selection in the art. In a specific embodiment, the barium salt is selected from barium nitrate and / or barium chloride.

[0094] In step (3) of the present application, the method for impregnation is not particularly limited, and the active component precursor and, optionally, the additive precursor are impregnated onto the molecular sieve to ultimately obtain the required supported deoxygenation catalyst.

[0095] In a specific embodiment of the present application, the method for impregnation is an equal-volume impregnation method. When the supported deoxygenation catalyst does not contain an additive, the specific operation in step (3) of impregnating the active component precursor onto the molecular sieve obtained in step (2) comprises: mixing the active component precursor with water to obtain an active component precursor solution, mixing and stirring the active component precursor solution with the molecular sieve, and then aging at room temperature. When the supported deoxygenation catalyst contains an additive, the specific operation in step (3) of impregnating the active component precursor and the additive precursor onto the molecular sieve obtained in step (2) comprises: mixing the active component precursor, the additive precursor, and water to obtain an active component precursor mixed solution, mixing and stirring the active component precursor mixed solution with the molecular sieve, and then aging at room temperature.

[0096] In step (3) of the present application, the amounts of the molecular sieve, the active component precursor, and the additive precursor are such that the contents of the active component and the additive in the ultimately obtained supported deoxygenation catalyst meet the requirements.

[0097] In a preferred embodiment, the room temperature refers to 20-30℃.

[0098] In step (3) of the present application, in order to ensure sufficient impregnation, the aging time is 1-3h.

[0099] In step (3) of the present application, the drying temperature is not particularly required, and water can be removed, and in a preferred embodiment, the drying temperature is 20-150℃.

[0100] In order to obtain a supported deoxidation catalyst with better performance, in a preferred embodiment, in step (3), the calcination conditions include: temperature of 350-700℃, and time of 1-10h.

[0101] In a specific embodiment, the calcination temperature in step (3) can be 350℃, 400℃, 500℃, 600℃ or 700℃, and the calcination time can be 1h, 3h, 5h, 7h or 10h.

[0102] The preparation method of the supported deoxidation catalyst can more quickly and efficiently prepare the carrier, uses a one-step method to synthesize the carrier, avoids subsequent acid and alkali treatment processes, ensures high crystallinity of the material, and introduces active centers by impregnation, which makes the preparation method of the supported deoxidation catalyst have the advantages of rapidity and efficiency and high reaction performance. The finally obtained supported deoxidation catalyst has more excellent reaction performance, high dispersion of active centers, stable reaction performance, high reaction activity, and the characteristics of low catalytic deoxidation reaction temperature, can be used in the field of deoxidation of oxygen-containing organic gas, is widely used in chemical processes, and can be applied to HPPO method propylene oxide device, ethylene method ethylene oxide, hydrogen peroxide method epichlorohydrin, etc. Chemical devices, and has broad application prospects for oxygen-containing organic gas produced in coal chemical industry, fine chemical industry and other fields.

[0103] The third aspect of the present application provides a method for deoxidation of olefins, which comprises: deoxidation reaction of raw gas containing propylene and oxygen with the above-mentioned supported deoxidation catalyst.

[0104] In a preferred embodiment of the present application, the content of oxygen in the raw gas is 1-5% by volume, and specifically can be 1% by volume, 2% by volume, 3% by volume, 4% by volume or 5% by volume.

[0105] Preferably, the deoxidation reaction conditions include: reaction space velocity of 1000-10000h -1 , temperature of 200-250℃, and pressure of 0.2-1MPa.

[0106] In a specific embodiment, the reaction space velocity of the deoxidation reaction can be 1000h -1 , 3000h-1 , 5000h -1 , 7000h -1 or 10000h -1 The temperature of the deoxidation reaction can be 200℃, 210℃, 220℃, 230℃, 240℃ or 250℃, and the pressure of the deoxidation reaction can be 0.2 MPa, 0.5 MPa, 0.7 MPa or 1 MPa.

[0107] In the present application, “space velocity” refers to “volume space velocity”, and pressure refers to absolute pressure.

[0108] The present application will be described in detail below through examples, but the scope of protection of the present application is not limited thereto.

[0109] In the following examples and comparative examples, the reagents used are all common commercially available products unless otherwise specified.

[0110] In the following examples and comparative examples:

[0111] The fine silica gel is inorganic silica gel with a chemical formula of SiO2, which is purchased from Aldrich Reagent;

[0112] The coarse silica gel is inorganic silica gel with a chemical formula of SiO2, which is purchased from Aldrich Reagent;

[0113] The attapulgite is a magnesium aluminum silicate with a chemical composition of 603SiO2.Al2O3.3MgO, which is purchased from National Pharmaceutical Group;

[0114] The white carbon black has a chemical formula of SiO2, which is purchased from Aldrich Reagent;

[0115] The seed crystal is a Beta molecular sieve, which is purchased from Sinopec Catalyst Company

[0116] The following room temperature refers to 25℃.

[0117] Example 1

[0118] (1) 15 g of fine silica gel, 0.68 g of sodium metaaluminate, 10 g of a tetraethylammonium hydroxide aqueous solution (concentration of 35 wt%) were uniformly mixed, 0.6 g of sodium hydroxide and 1.0 g of seed crystal were added and uniformly stirred to obtain a raw material mixture; wherein the molar ratio of the amounts of fine silica gel (calculated as SiO2), sodium metaaluminate (calculated as Al2O3), tetraethylammonium hydroxide, sodium hydroxide and water is 16.6:0.3:1.6:1:24.1; and the weight ratio of the total amount of fine silica gel (calculated as SiO2) and sodium metaaluminate (calculated as Al2O3) to the amount of seed crystal is 100:6.5;

[0119] (2) The raw material mixture is transferred to a polytetrafluoroethylene liner, and after standing for 10 h, the liner is placed in a preheated stainless steel reaction kettle, crystallized at 180 °C for 50 min, and after crystallization is completed, the obtained product is washed with deionized water and centrifuged, dried at 100 °C after removing the water, and then calcined at 550 °C for 5 h to obtain a molecular sieve; the molecular sieve is tested by XRD to confirm that the molecular sieve is a Beta molecular sieve, and the XRD pattern is shown in Figure 1 The grain size of the molecular sieve is 50-300 nm detected by SEM, the nitrogen adsorption-desorption curve of the molecular sieve is tested by BET to calculate the specific surface area of 416 m 2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve is tested and calculated by inductively coupled plasma atomic emission spectrometry to be 48:1.

[0120] (3) The active component precursor (palladium nitrate) and the additive precursor (potassium nitrate) are impregnated onto the molecular sieve obtained in step (2) by using an equal volume impregnation method, and the specific operation includes: mixing the active component precursor and the additive precursor with water to obtain an active component precursor mixed solution, adding the active component precursor mixed solution (containing 0.5 g of Pd element and 0.5 g of K element) into 99 g of the molecular sieve obtained in step (2), mixing uniformly, then aging at room temperature for 3 h, then drying at 40 °C to remove water, and then calcining at 400 °C for 3 h to obtain a supported deoxidation catalyst; according to ICP atomic emission spectrometry detection, the active component in the supported deoxidation catalyst is palladium, and the content of palladium is 0.5 wt%, and the additive is potassium, and the content of potassium is 0.5 wt%.

[0121] (4) The raw gas containing propylene and oxygen (99 vol% propylene and 1 vol% oxygen) is introduced into a fixed bed reactor packed with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction; the space velocity is 2500 h -1 , the temperature is 240 °C, and the pressure is 0.5 MPa; the oxygen content is monitored in real time by online detection using gas chromatography, and the oxygen content of the outlet gas is less than 0.05 vol%.

[0122] Example 2

[0123] (1) After uniformly mixing 10 g of white carbon black, 0.34 g of sodium aluminate, and 10 g of a tetraethylammonium hydroxide aqueous solution (with a concentration of 25 wt%), 0.5 g of sodium hydroxide and 0.5 g of seed crystals were added and stirred to obtain a raw material mixture; wherein the molar ratio of the amount of white carbon black (calculated as SiO2), sodium aluminate (calculated as Al2O3), tetraethylammonium hydroxide, sodium hydroxide, and water is 13.3:0.17:1.36:1:33.3; and the weight ratio of the total amount of white carbon black (calculated as SiO2) and sodium aluminate (calculated as Al2O3) to the amount of the seed crystal is 100:4.9;

[0124] (2) The raw material mixture is transferred to a polytetrafluoroethylene liner, and after standing for 12 hours, the liner is placed in a preheated stainless steel reactor and crystallized at 190°C for 45 minutes. After the crystallization is completed, the obtained product is washed with deionized water and centrifuged, and after removing the water, it is dried at 100°C and then calcined at 500°C for 5 hours to obtain a molecular sieve; the molecular sieve is confirmed to be a Beta molecular sieve by XRD testing, and the grain size of the molecular sieve is 50-250nm after SEM testing. The nitrogen adsorption-desorption curve of the molecular sieve is tested by BET, and the specific surface area is calculated to be 405m 2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was measured and calculated by inductively coupled plasma atomic emission spectroscopy to be 69:1;

[0125] (3) impregnating the active component precursor (palladium chloride) onto the molecular sieve obtained in step (2) by an equal volume impregnation method, wherein the specific operation comprises: mixing the active component precursor with water to obtain an active component precursor solution, adding the active component precursor solution (containing 0.1 g of Pd element) dropwise to 99.9 g of the molecular sieve obtained in step (2), mixing evenly, aging at room temperature for 3 h, then drying at 40° C. to remove moisture, and then calcining at 400° C. for 3 h to obtain a supported deoxidation catalyst, wherein the active component in the supported deoxidation catalyst is palladium, and the palladium content is 0.1 wt% according to ICP atomic emission spectroscopy;

[0126] (4) The feed gas containing propylene and oxygen (99% by volume propylene and 1% by volume oxygen) is introduced into a fixed bed reactor filled with the supported deoxygenation catalyst obtained in step (3) to carry out a gas phase deoxygenation reaction; the reaction space velocity is 1500 h -1 , temperature is 230°C, pressure is 0.5MPa; oxygen content is monitored in real time using gas chromatography online detection, and the oxygen content of the outlet gas is detected to be less than 0.1% by volume.

[0127] Example 3

[0128] (1) 10 g of crude silica gel, 0.5 g of sodium metaaluminate, 12 g of tetraethylammonium bromide aqueous solution (concentration of 55% by weight) were uniformly mixed, then 0.8 g of potassium hydroxide and 1.0 g of seed crystals were added and stirred to obtain a raw material mixture; wherein the molar ratio of the amounts of the crude silica gel (calculated as SiO2), sodium metaaluminate (calculated as Al2O3), tetraethylammonium bromide, potassium hydroxide and water was 11.7:0.2:2.2:1:21; the weight ratio of the total amount of the crude silica gel (calculated as SiO2) and sodium metaaluminate (calculated as Al2O3) to the amount of the seed crystals was 100:9.7;

[0129] (2) The raw material mixture was transferred to a polytetrafluoroethylene liner, and after standing for 8 h, the liner was placed in a preheated stainless steel reaction kettle, and crystallization was carried out at 160°C for 180 min. After crystallization was completed, the obtained product was washed with deionized water and centrifuged, dried at 100°C after removing the water, and then calcined at 600°C for 5 h to obtain a molecular sieve. The molecular sieve was tested by XRD to confirm that the molecular sieve was a Beta molecular sieve. The crystal grain size of the molecular sieve was 100-300 nm detected by SEM. The nitrogen adsorption-desorption curve of the molecular sieve was tested by BET to calculate the specific surface area of the molecular sieve, which was 394 m2 / g. The silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was tested and calculated by inductively coupled plasma atomic emission spectrometry, which was 57:1; 2

[0130] (3) The active component precursor (palladium nitrate) was impregnated onto the molecular sieve obtained in step (2) by using an equal volume impregnation method. The specific operation included: mixing the active component precursor with water to obtain an active component precursor solution, adding the active component precursor solution (containing 0.8 g of Pd element) dropwise into 99.2 g of the molecular sieve obtained in step (2), uniformly mixing, then aging at room temperature for 3 h, then drying at 40°C to remove water, and then calcining at 400°C for 3 h to obtain a supported deoxidation catalyst. The active component in the supported deoxidation catalyst was palladium, and the content of palladium was 0.8 wt% detected by ICP atomic emission spectrometry.

[0131] (4) The raw gas containing propylene and oxygen (95% by volume of propylene and 5% by volume of oxygen) was introduced into a fixed bed reactor packed with the supported deoxidation catalyst obtained in step (3) to carry out a gas phase deoxidation reaction; the space velocity was 1500 h-1, the temperature was 220°C, and the pressure was 0.5 MPa; the oxygen content was monitored in real time by online detection using gas chromatography, and the oxygen content of the outlet gas was less than 0.3% by volume. -1

[0132] Example 4

[0133] ​​(1) After uniformly mixing 10 g of attapulgite, 0.6 g of sodium aluminate, and 15 g of tetraethylammonium bromide aqueous solution (with a concentration of 45 wt%), 0.5 g of sodium hydroxide and 0.8 g of seed crystals were added and stirred to obtain a raw material mixture; wherein the molar ratio of the attapulgite (calculated as SiO2), sodium aluminate (calculated as Al2O3), tetraethylammonium bromide, sodium hydroxide, and water is 13.3:0.3:2.6:1:36.7; and the weight ratio of the total amount of attapulgite (calculated as SiO2) and sodium aluminate (calculated as Al2O3) to the amount of the seed crystal is 100:7.7;

[0134] (2) The raw material mixture is transferred to a polytetrafluoroethylene liner, and after standing for 9 hours, the liner is placed in a preheated stainless steel reactor and crystallized at 180°C for 50 minutes. After the crystallization is completed, the obtained product is washed with deionized water and centrifuged, and after removing the water, it is dried at 100°C and then calcined at 600°C for 7 hours to obtain a molecular sieve; the molecular sieve is confirmed to be a Beta molecular sieve by XRD testing, and the grain size of the molecular sieve is 150-260nm after SEM testing. The nitrogen adsorption-desorption curve of the molecular sieve is tested by BET, and the specific surface area is calculated to be 398m 2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was measured and calculated by inductively coupled plasma atomic emission spectroscopy to be 46:1;

[0135] (3) impregnating the active component precursor (chloropalladic acid) onto the molecular sieve obtained in step (2) by an equal volume impregnation method, wherein the specific operation comprises: mixing the active component precursor with water to obtain an active component precursor solution, adding the active component precursor solution (containing 1 g of Pd element) dropwise into 99 g of the molecular sieve obtained in step (2), mixing evenly, aging at room temperature for 1 h, then drying at room temperature to remove moisture, and then calcining at 450° C. for 8 h to obtain a supported deoxygenation catalyst, wherein the active component in the supported deoxygenation catalyst is palladium, and the palladium content is 1 wt% according to ICP atomic emission spectroscopy;

[0136] (4) The feed gas containing propylene and oxygen (95% by volume of propylene and 5% by volume of oxygen) is introduced into a fixed bed reactor filled with the supported deoxygenation catalyst obtained in step (3) to carry out a gas phase deoxygenation reaction; the reaction space velocity is 1500 h -1 , temperature is 220°C, pressure is 0.5MPa; oxygen content is monitored in real time using gas chromatography online detection, and the oxygen content of the outlet gas is detected to be less than 0.3% by volume.

[0137] Example 5

[0138] (1) 12 g of the attapulgite, 1 g of sodium metaaluminate, 15 g of a tetraethylammonium bromide aqueous solution (concentration of 30% by weight) were uniformly mixed, 0.5 g of sodium hydroxide and 0.5 g of seed crystals were added and stirred to obtain a raw material mixture; wherein the molar ratio of the amounts of the attapulgite (calculated as SiO2), the sodium metaaluminate (calculated as Al2O3), the tetraethylammonium bromide, the sodium hydroxide and water was 16:0.49:1.7:1:46.7; and the weight ratio of the total amount of the attapulgite (calculated as SiO2) and the sodium metaaluminate (calculated as Al2O3) to the amount of the seed crystals was 100:4;

[0139] (2) The raw material mixture was transferred into a polytetrafluoroethylene liner, and after being left to stand for 11 h, the liner was put into a preheated stainless steel reaction kettle, and the mixture was crystallized at 180 °C for 50 min. After the crystallization was completed, the obtained product was washed with deionized water and centrifuged, dried at 100 °C after removing the water, and then calcined at 600 °C for 2 h to obtain a molecular sieve. The molecular sieve was tested by XRD and confirmed to be a Beta molecular sieve. The crystal grain size of the molecular sieve was 100-300 nm as detected by SEM. The nitrogen adsorption-desorption curve of the molecular sieve was tested by BET, and the specific surface area was calculated to be 410 m2 / g. The silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was calculated to be 35:1 by inductively coupled plasma atomic emission spectrometry. 2

[0140] (3) The active component precursor (chloropalladic acid) was impregnated onto the molecular sieve obtained in step (2) by using an equal-volume impregnation method. The specific operation included: the active component precursor was mixed with water to obtain an active component precursor solution, the active component precursor solution (containing 0.5 g of Pd element) was added dropwise into 99.5 g of the molecular sieve obtained in step (2), and then uniformly mixed. After being left to stand at room temperature for 1 h, the water was removed by drying at room temperature, and then the active component precursor was calcined at 450 °C for 10 h to obtain a supported deoxidation catalyst. The active component in the supported deoxidation catalyst was palladium as detected by ICP atomic emission spectrometry, and the content of palladium was 0.5 wt%.

[0141] (4) The raw gas containing propylene and oxygen (95% by volume of propylene and 5% by volume of oxygen) was introduced into a fixed bed reactor filled with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction. The space velocity was 1500 h-1, the temperature was 220 °C, and the pressure was 0.5 MPa. The oxygen content was monitored in real time by using gas chromatography for online detection, and the oxygen content of the outlet gas was less than 0.5% by volume. -1

[0142] Example 6

[0143] ​​The molecular sieve prepared in Example 1 was used to prepare a supported deoxidation catalyst, wherein the active component precursor used in step (3) was platinum chloride, and the specific operations of steps (3) and (4) were as follows:

[0144] (3) The active component precursor (platinum chloride) was impregnated onto the molecular sieve obtained in step (2) by using the equal volume impregnation method. The specific operation included: the active component precursor was mixed with water to obtain an active component precursor solution, the active component precursor solution (containing 0.8 g of Pt element) was added dropwise into 99.2 g of the molecular sieve obtained in step (2), and then the mixture was uniformly mixed, aged at room temperature for 2 h, dried at 100 ℃ to remove water, and then calcined at 600 ℃ for 10 h to obtain a supported deoxidation catalyst. According to ICP atomic emission spectrometry detection, the active component in the supported deoxidation catalyst was platinum, and the content of platinum was 0.8 wt%;

[0145] (4) The raw material gas containing propylene and oxygen (96 vol% propylene and 4 vol% oxygen) was introduced into a fixed bed reactor filled with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction; the reaction space velocity was 7000 h-1, the temperature was 200 ℃, and the pressure was 0.8 MPa; the oxygen content was monitored in real time by using gas chromatography for online detection, and the outlet gas oxygen content was less than 0.1 vol%. -1

[0146] Example 7

[0147] The molecular sieve prepared in Example 2 was used to prepare a supported deoxidation catalyst, wherein the active component precursor used in step (3) was platinum chloride, and the specific operations of steps (3) and (4) were as follows:

[0148] (3) The active component precursor (platinum chloride) was impregnated onto the molecular sieve obtained in step (2) by using the equal volume impregnation method. The specific operation included: the active component precursor was mixed with water to obtain an active component precursor solution, the active component precursor solution (containing 0.8 g of Pt element) was added dropwise into 99.2 g of the molecular sieve obtained in step (2), and then the mixture was uniformly mixed, aged at room temperature for 2 h, dried at 100 ℃ to remove water, and then calcined at 600 ℃ for 10 h to obtain a supported deoxidation catalyst. According to ICP atomic emission spectrometry detection, the active component in the supported deoxidation catalyst was platinum, and the content of platinum was 0.8 wt%;

[0149] (4) The raw material gas containing propylene and oxygen (96 vol% propylene and 4 vol% oxygen) was introduced into a fixed bed reactor filled with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction; the reaction space velocity was 7000 h-1, the temperature was 200 ℃, and the pressure was 0.8 MPa; the oxygen content was monitored in real time by using gas chromatography for online detection, and the outlet gas oxygen content was less than 0.1 vol%.​-1 The temperature was 230 DEG C, and the pressure was 0.3 MPa; the oxygen content was monitored in real time by using gas chromatography for online detection, and the oxygen content of the outlet gas was less than 0.3% by volume.

[0150] Example 8

[0151] (1) 30 g of attapulgite, 8.2 g of sodium metaaluminate, 33 g of a tetraethylammonium bromide aqueous solution (concentration of 40% by weight) were uniformly mixed, 1 g of sodium hydroxide and 0.5 g of seeds were added and uniformly stirred to obtain a raw material mixture; wherein the molar ratio of the amounts of attapulgite (calculated as SiO2), sodium metaaluminate (calculated as Al2O3), tetraethylammonium bromide, sodium hydroxide and water was 20:2:2.5:1:44; and the weight ratio of the total amount of attapulgite (calculated as SiO2) and sodium metaaluminate (calculated as Al2O3) to the amount of seeds was 100:0.62;

[0152] (2) The raw material mixture was transferred to a polytetrafluoroethylene liner, and after standing for 9 h, the liner was placed in a preheated stainless steel reaction kettle, and crystallization was carried out at 190 DEG C for 60 min; after crystallization was completed, the obtained product was washed with deionized water and centrifuged, dried at 110 DEG C after removing the water, and then calcined at 550 DEG C for 7 h to obtain a molecular sieve; the molecular sieve was confirmed to be a Beta molecular sieve by XRD testing, the crystal grain size of the molecular sieve was 120-280 nm by SEM testing, the nitrogen adsorption-desorption curve of the molecular sieve was tested by BET, and the specific surface area was calculated to be 382 m2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was calculated to be 11 by inductively coupled plasma atomic emission spectrometry testing; 2

[0153] (3) The active component precursor (platinum acetate) and the additive precursor (lithium nitrate and magnesium chloride) were impregnated onto the molecular sieve obtained in step (2) by using an equal-volume impregnation method; the specific operation included: the active component precursor and the additive precursor were mixed with water to obtain an active component precursor mixed solution, the active component precursor mixed solution (containing 0.5 g of Pt element, 2 g of Li element and 2 g of Mg element) was added dropwise into 95.5 g of the molecular sieve obtained in step (2), and uniformly mixed; after aging at room temperature for 2 h, the water was removed by drying at room temperature, and then calcination was carried out at 650 DEG C for 2 h to obtain a supported deoxidation catalyst; the active component in the supported deoxidation catalyst was platinum, and the content of platinum was 0.5 wt%, the additive was potassium and magnesium, and the content of potassium was 2 wt% and the content of magnesium was 2 wt% according to ICP atomic emission spectrometry detection;

[0154] ​(4) The raw material gas containing propylene and oxygen (99% by volume of propylene and 1% by volume of oxygen) was introduced into a fixed bed reactor filled with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction; the space velocity was 1000 h-1, the temperature was 250°C, and the pressure was 1 MPa; the oxygen content was monitored in real time using gas chromatography for online detection, and the oxygen content of the outlet gas was less than 0.05% by volume. -1 2

[0155] Example 9

[0156] (1) 120.2 g of attapulgite, 65.6 g of sodium metaaluminate, 175 g of a tetraethylammonium bromide aqueous solution (concentration of 30% by weight) were uniformly mixed, 2 g of sodium hydroxide and 3.22 g of seeds were added and uniformly stirred to obtain a raw material mixture; the molar ratio of the amounts of attapulgite (calculated as SiO2), sodium metaaluminate (calculated as Al2O3), tetraethylammonium bromide, sodium hydroxide and water was 40:8:5:1:136; and the weight ratio of the total amount of attapulgite (calculated as SiO2) and sodium metaaluminate (calculated as Al2O3) to the amount of the seeds was 100:2;

[0157] (2) The raw material mixture was transferred to a polytetrafluoroethylene liner, the liner was placed in a preheated stainless steel reaction kettle after being left to stand for 12 h, and crystallization was performed at 160°C for 180 min; after the crystallization was completed, the obtained product was washed with deionized water and centrifuged, dried at 100°C after removing the water, and then calcined at 600°C for 3 h to obtain a molecular sieve; the molecular sieve was confirmed to be a Beta molecular sieve using XRD testing, the crystal grain size of the molecular sieve was 50-290 nm as detected by SEM, the nitrogen adsorption-desorption curve of the molecular sieve was tested by BET, the specific surface area was calculated to be 381 m2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve was calculated to be 16 by inductively coupled plasma atomic emission spectrometry testing; 2

[0158] ​(3) The active component precursor (platinum chloride and palladium nitrate) and the assistant precursor (calcium chloride and barium nitrate) are impregnated on the molecular sieve obtained in step (2) by using an equal volume impregnation method. The specific operation includes: mixing the active component precursor and the assistant precursor with water to obtain an active component precursor mixed solution, adding the active component precursor mixed solution (containing 0.5 g of Pt element, 0.5 g of Pd element, 2 g of Ca element and 1 g of Ba element) into 96 g of the molecular sieve obtained in step (2), uniformly mixing, then aging for 2 h at room temperature, then drying to remove water at room temperature, and then calcining at 450 ℃ for 10 h to obtain a supported deoxidation catalyst. According to ICP atomic emission spectrometry detection, the active component in the supported deoxidation catalyst is platinum and palladium, the content of platinum is 0.5 wt%, the content of palladium is 0.5 wt%, the assistant is calcium and barium, and the content of calcium is 2 wt% and the content of barium is 1 wt%;

[0159] (4) The raw material gas containing propylene and oxygen (99% by volume of propylene and 1% by volume of oxygen) is introduced into a fixed bed reactor filled with the supported deoxidation catalyst obtained in step (3) to perform a gas phase deoxidation reaction; the space velocity is 7000 h-1, the temperature is 230 ℃, and the pressure is 0.5 MPa; the oxygen content is monitored in real time by using gas chromatography online detection, and the oxygen content of the outlet gas is less than 0.05% by volume. -1

[0160] Comparative Example 1

[0161] The method of Example 1 is followed, except that the template agent is replaced by tetramethylammonium hydroxide instead of tetraethylammonium hydroxide; the molecular sieve is prepared, the XRD spectrum shows that the material prepared in this comparative example is an amorphous structure, the nitrogen adsorption-desorption curve of the molecular sieve is tested by using BET, and the specific surface area is calculated to be 103 m 2 / g, and the silicon-aluminum molar ratio (SiO2 / Al2O3) of the molecular sieve is tested and calculated by using inductively coupled plasma atomic emission spectrometry to be 51:1; it can be seen that, in the present application, if tetraethylammonium hydroxide is not used as the template agent, the Beta molecular sieve with high crystallinity described in the present application cannot be obtained;

[0162] The molecular sieve is prepared into a supported deoxidation catalyst according to the method of Example 1, and the gas phase deoxidation reaction is performed according to the method of Example 1; the oxygen content is monitored in real time by using gas chromatography online detection, and the oxygen content of the outlet gas is 0.61% by volume.

[0163] Comparative Example 2

[0164] ​The process of Example 1 was followed except that the amount of fine silica gel was 0.045 g and the amount of seed crystals was 0.03 g, i.e. the molar ratio of the amounts of fine silica gel (calculated as Si02), sodium metaaluminate (calculated as Al203), tetraethylammonium hydroxide, sodium hydroxide and water was 0.05:0.3:1.6:1:24.1; the weight ratio of the total amount of fine silica gel (calculated as Si02) and sodium metaaluminate (calculated as Al203) to the amount of seed crystals was 100:6.5; a molecular sieve was prepared, which was confirmed to be amorphous structure using XRD test, the nitrogen adsorption-desorption curve of the molecular sieve was tested by BET, the specific surface area was calculated to be 56 m2 / g, the molar ratio of silicon and aluminum (Si02 / Al203) of the sample was calculated to be 0.18 using inductively coupled plasma atomic emission spectrometry test; 2

[0165] The molecular sieve was prepared into a supported deoxidation catalyst and was used in a gas phase deoxidation reaction according to the process of Example 1, the oxygen content was monitored in real time using gas chromatography online detection, and the outlet gas oxygen content was detected to be 0.55 vol%.

[0166] Comparative Example 3

[0167] The process of Example 1 was followed except that the amount of fine silica gel was 252.35 g and the amount of seed crystals was 16.43 g, i.e. the molar ratio of the amounts of fine silica gel (calculated as Si02), sodium metaaluminate (calculated as Al203), tetraethylammonium hydroxide, sodium hydroxide and water was 280:0.3:1.6:1:24.1; the weight ratio of the total amount of fine silica gel (calculated as Si02) and sodium metaaluminate (calculated as Al203) to the amount of seed crystals was 100:6.5; a product was prepared, which was confirmed to be amorphous structure using XRD test, the nitrogen adsorption-desorption curve of the molecular sieve was tested by BET, the specific surface area was calculated to be 98 m2 / g, the molar ratio of silicon and aluminum (Si02 / Al203) of the sample was calculated to be 881 using inductively coupled plasma atomic emission spectrometry test; 2

[0168] The molecular sieve was prepared into a supported deoxidation catalyst and was used in a gas phase deoxidation reaction according to the process of Example 1, the oxygen content was monitored in real time using gas chromatography online detection, and the outlet gas oxygen content was detected to be 0.66 vol%.

[0169] Comparative Example 4

[0170] ​​The method according to example 1 was followed, except that 0.123 g of sodium metaaluminate was used, and 0.98 g of seed crystals, i.e. the molar ratio of the amounts of fine silica gel (calculated as SiO2), sodium metaaluminate (calculated as Al2O3), tetraethylammonium hydroxide, sodium hydroxide and water was 16.6:0.05:1.6:1:24.1; and the weight ratio of the total amount of fine silica gel (calculated as SiO2) and sodium metaaluminate (calculated as Al2O3) to the amount of seed crystals was 100:6.5; to obtain a molecular sieve, which was confirmed to be amorphous by XRD test, and the specific surface area of the molecular sieve was calculated to be 76 m2 / g by BET test using nitrogen adsorption-desorption curve of the molecular sieve, and the molar ratio of silicon to aluminum (SiO2 / Al2O3) of the molecular sieve was calculated to be 300 by inductively coupled plasma atomic emission spectrometry test. 2

[0171] The molecular sieve was also prepared into a supported deoxidation catalyst according to the method of example 1, and was used in a gas phase deoxidation reaction, and the oxygen content was monitored in real time by online detection using gas chromatography, and the oxygen content of the outlet gas was detected to be 0.76 vol%.

[0172] From the above results, it can be seen that the supported deoxidation catalyst prepared from the molecular sieve of the present application has good deoxidation effect and stable performance.

[0173] The above describes the preferred embodiments of the present application in detail, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed content of the present application, and all fall within the protection scope of the present application.​

Claims

1. A supported deoxidation catalyst, characterized in that: The supported deoxidation catalyst comprises a carrier, an active component supported on the carrier, and an optional auxiliary agent; The carrier is a molecular sieve with a crystal size of 50-300 nm and a specific surface area of ​​350-450 m 2 / g; silicon-aluminum molar ratio is 10-80:1; The active component is a precious metal; The auxiliary agent is an alkali metal and / or an alkaline earth metal.

2. The supported deoxidation catalyst according to claim 1, characterized in that The noble metal is Pd and / or Pt; Preferably, the alkali metal is selected from one or more of Li, Na and K; Preferably, the alkaline earth metal is selected from one or more of Mg, Ca and Ba.

3. The supported deoxidation catalyst according to claim 1 or 2, characterized in that In the molecular sieve, the molar ratio of silicon to aluminum is 10-60:

1.

4. The supported deoxidation catalyst according to claim 1, characterized in that The supported deoxidation catalyst contains 0.1-1 wt% of active components; Preferably, when the supported deoxygenation catalyst contains an auxiliary agent, the supported deoxygenation catalyst contains 0.5-5 wt% of the auxiliary agent.

5. A method for preparing the supported deoxidation catalyst according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) mixing a silicon source, an aluminum source, a template, an alkali, a seed crystal, and water to obtain a raw material mixture; (2) allowing the raw material mixture to stand, crystallize, and calcine in sequence to obtain a molecular sieve; (3) impregnating the active component precursor and the optional auxiliary agent precursor onto the molecular sieve obtained in step (2), followed by drying and calcining; Wherein, the template is tetraethylammonium hydroxide and / or tetraethylammonium bromide, and the molar ratio of the silicon source, aluminum source, template, alkali and water is 0.1-250:0.1-18:0.3-42:1:5-625, the silicon source is calculated as SiO2, and the aluminum source is calculated as Al2O3; The weight ratio of the total amount of the silicon source and the aluminum source to the amount of the seed crystal is 100:0.5-10; The active component precursor is a noble metal salt; the auxiliary agent precursor is an alkali metal salt and / or an alkaline earth metal salt.

6. The method according to claim 5, characterized in that In step (1), the molar ratio of the silicon source, the aluminum source, the template, the base and the water is 0.2-200:0.15-15:0.4-40:1:7-623, wherein the silicon source is calculated as SiO2 and the aluminum source is calculated as Al2O3; Preferably, the aluminum source is selected from one or more of sodium metaaluminate, aluminum hydroxide and pseudo-boehmite; Preferably, the silicon source is selected from one or more of silica gel, attapulgite and white carbon black; Preferably, the base is selected from one or more of sodium hydroxide, potassium hydroxide and sodium carbonate.

7. The method according to claim 5 or 6, characterized in that In step (2), the standing time is 8-12 hours.

8. The method according to claim 5, characterized in that In step (2), the crystallization conditions include: temperature of 160-190° C. and time of 30-180 min.

9. The method according to claim 5 or 8, characterized in that In step (2), the calcination conditions include: temperature of 500-600° C. and time of 1-10 h.

10. The method according to claim 5, characterized in that The noble metal salt is selected from palladium-containing compounds and / or platinum-containing compounds; Preferably, the alkali metal salt is selected from one or more of lithium salt, sodium salt and potassium salt; Preferably, the alkaline earth metal salt is selected from one or more of magnesium salt, calcium salt and barium salt.

11. The method according to claim 5 or 10, characterized in that In step (3), the calcination conditions include: temperature of 350-700° C. and time of 1-10 h.

12. A method for deoxygenating olefins, characterized in that: The method comprises: subjecting a feed gas containing propylene and oxygen to a deoxygenation reaction with the supported deoxygenation catalyst according to any one of claims 1 to 4.

13. The method according to claim 12, characterized in that The oxygen content in the raw gas is 1-5% by volume.

14. The method according to claim 12 or 13, characterized in that The conditions of the deoxygenation reaction include: a reaction space velocity of 1000-10000h -1 , temperature is 200-250℃, and pressure is 0.2-1MPa.

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