A heteroatom-modified SiO2-supported copper oxide catalyst, a preparation method and applications thereof

Abstract

The application provides a kind of heteroatom modified SiO2 Supported copper oxide catalyst and its preparation method and application, it is related to catalysis technical field.The catalyst is with copper oxide as active component, with one or several of heteroatom Ce, Zr, Mo, V modified mesoporous spherical SiO2 As carrier, utilize the active center of stable catalyst surface of multivalent heteroatom oxide, in diethylene glycol dehydrogenation cyclization preparation 1,4-dioxane-2-ketone reaction, realizes diethylene glycol conversion rate >99%, 1,4-dioxane-2-ketone yield >98% Excellent activity, in continuous operation of 500 hours continuously does not deactivate.The application overcomes the deficiency of prior art, realizes diethylene glycol high-efficiency conversion to 1,4-dioxane-2-ketone under mild conditions, has wide industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysis technology, in particular to a heteroatom modified SiO2 supported copper oxide catalyst and a preparation method and application thereof. BACKGROUND

[0002] Diethylene glycol is mainly a byproduct from the deep hydration conversion of ethylene glycol in the hydration of ethylene oxide to produce ethylene glycol, and its production capacity accounts for about 10% of the production capacity of ethylene oxide method for producing ethylene glycol. In recent years, with the continuous increase of ethylene oxide method for producing ethylene glycol devices, the diethylene glycol production capacity has reached the level of millions of tons. However, the downstream of diethylene glycol is mainly to produce brake fluid, solvent, gas dehydrating agent, plasticizer, and polyurethane resin, and the demand for application fields is less, resulting in a continuous decline in the price of diethylene glycol product. Therefore, expanding the downstream application field of diethylene glycol and developing high-value downstream products can help to solve the contradiction between supply and demand of diethylene glycol and improve the production efficiency of the device. Among them, the oxidation dehydrogenation of diethylene glycol to produce 1,4-dioxane-2-ketone (PDO) is one of the most potential routes. The target product of this reaction, PDO, is a six-membered heterocyclic lactone compound containing ester and ether bonds in its structure. It can not only be used as a mildew inhibitor, but also is the main monomer for synthesizing biodegradable and bioabsorbable material poly-1,4-dioxane-2-ketone (PPDO) and its derivatives. This kind of polymer has unique biodegradable and bioabsorbable properties, and is commonly used as surgical suture material, artificial bone tissue repair material, drug release carrier, etc. in the medical field. However, how to realize the high-purity and large-scale synthesis of PDO monomer is the key to reducing the price of PDO and realizing its large-scale application.

[0003] At present, the preparation process of PDO can be divided into five categories according to different paths:

[0004] 1. Using 2,3-dichloro-1,4-dioxane as raw material, pyrolysis to remove one molecule of HCl to obtain 2-chlorodioxin, and then reacting with alcohol to obtain PDO product. This path has the disadvantages of narrow raw material source, high pyrolysis temperature, easy production of corrosive by-products, and low yield.

[0005] 2. Using ethylene glycol as raw material, catalyzing ethylene glycol and CO, formaldehyde carbonylation reaction to obtain PDO. This reaction needs to use HF and copper carbonyl complex as catalyst, which causes high catalyst cost and high safety risk of this path.

[0006] 3. Using ethylene glycol as raw material, first reacting with sodium to obtain ethylene glycol monosodium, then reacting with sodium chloroacetate to obtain β-hydroxyethoxy sodium acetate, and then converting into the target product 1,4-dioxane-2-ketone in the presence of acid and magnesium sulfate. This path has the disadvantages of complicated reaction path, long steps, and generation of a large amount of by-product salt in the reaction process.

[0007] 4. With diethylene glycol as raw material, the terminal alcohol on one end of diethylene glycol is dehydrogenated to obtain a terminal aldehyde under the action of a catalyst, then the aldehyde and the alcohol on the other end are subjected to aldol condensation and cyclization to obtain 1,4-dioxane-2-alcohol, and finally the 1,4-dioxane-2-alcohol is subjected to oxidation and dehydrogenation to obtain PDO. This path has the advantages of short reaction path and high yield.

[0008] 5. With glycolate and ethylene oxide as raw materials, the target product PDO is obtained through ethylene oxide ring-opening reaction and intramolecular ester exchange reaction under the action of an acid / base catalyst. Although this path uses bulk chemicals as raw materials, there is a competitive ethylene oxide ring-opening polymerization side reaction in the reaction process, which produces polyethylene glycol oligomers and other by-products, and the catalysts used are mostly homogeneous catalysts, causing difficulty in subsequent purification.

[0009] Therefore, compared with other paths, the diethylene glycol oxidation and dehydrogenation path for preparing PDO has the advantages of easy availability of raw materials, short reaction path, easy separation of product, high yield, etc., and has strong competitiveness. The core of this path is the development of high-efficiency catalysts. US2807629 and US2900395 disclose a catalyst in which copper chromite is used as an active species to catalyze the oxidation and dehydrogenation of diethylene glycol under hydrogen at 250-287°C to prepare PDO by cyclization, and the yield of the target product reaches 81-84%. However, the catalyst contains Cr element, which limits the application of the product. -7 equivalent / m 2 CN112724122A discloses a heterogeneous catalyst in which hydroxyapatite is used as a carrier to load Ru, Pd, Ir, Pt, V, Cr, Fe, Co, Ni, Cu and Zn, and in a batch reactor, water, methanol or ethanol, etc. are used as solvents to realize the efficient conversion of diethylene glycol to PDO, and the yield reaches 100%. Patent CN115970747A discloses a catalyst in which heteroatom beta molecular sieve is used as a carrier to load copper oxide and vanadium oxide, and under the conditions of a mass ratio of reactant to catalyst of 10-1000, a reaction temperature of 180-240°C, and a residence time of 0.1-10 h-1, the yield of PDO prepared by catalytic conversion of diethylene glycol reaches a maximum of 88.2%.

[0010] Although the above patent discloses a series of catalyst systems applied to the reaction, there are still defects such as insufficient long-period running life (<100 hours), high requirement for carriers and high difficulty in carrier preparation, which limit the industrial application of these catalysts. According to the literature summary and reaction mechanism, the catalysts for the catalytic conversion of diethylene glycol to 1,4-dioxane-2-ketone are mainly copper and zinc with oxidation dehydrogenation activity. The key to obtaining excellent catalytic activity is to select a suitable carrier and an additive to realize the synergistic performance of the three consecutive reaction steps of dehydrogenation of the alcohol end group of diethylene glycol, aldol condensation and oxidation dehydrogenation of the hydroxyl group. The key to long-period running is to construct an oxidation-reduction cycle system on the surface of the catalyst to maintain the oxidation-reduction property of the active center of the catalyst and ensure the long-period running of the catalyst. SUMMARY

[0011] In view of the deficiencies of the prior art, the present application provides a heteroatom-modified SiO2-supported copper oxide catalyst, a preparation method and application thereof. The catalyst is a heterogeneous catalyst with a mesoporous silica modified by a multi-valence heteroatom oxide as a carrier and copper oxide loaded thereon, which can efficiently catalyze the dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone. The method can realize the continuous and long-period running of the target product 1,4-dioxane-2-ketone under mild conditions.

[0012] To achieve the above object, the present application is implemented by the following technical solutions:

[0013] A heteroatom-modified SiO2-supported copper oxide catalyst, which is composed of the following components in mass percentage: 1%-5% of a heteroatom, 5%-40% of an active component, and the balance of SiO2. The heteroatom is one or more of Ce, Zr, Mo and V, and the active component is copper oxide. The catalyst has a SiO2 carrier modified by a heteroatom.

[0014] Preferably, the SiO2 has a specific surface area of 300-600 m 2 / g, a pore size of 5-30 nm, and is spherical silica.

[0015] The preparation method of the heteroatom-modified SiO2-supported copper oxide catalyst comprises the following steps:

[0016] (1) SiO2 is immersed in an equal volume of a solvent containing a heteroatom metal precursor, ultrasonically dispersed for 10-30 min, and then dried at 70-90℃ for 4-8 h. The product is ground and calcined at 500-700℃ for 3-8 h to obtain SiO2 modified by a heteroatom, denoted as M-SiO2;

[0017] (2) The M-SiO2 is immersed in a solvent containing a Cu source, ultrasonic dispersion for 10-30 min, and then dried at 70-90℃ for 2-6 h; then the obtained powder is ground thoroughly and calcined at 400-700℃ for 2-8 h to obtain CuO supported by atomically modified SiO2 x The catalyst raw powder is denoted as CuO x / M-SiO2.

[0018] (3) The CuO x / M-SiO2 is pressed into tablets, granulated, and sieved to 40-60 mesh to obtain the catalyst.

[0019] Preferably, the heteroatom metal precursor in step (1) is any one or more of ammonium cerous nitrate, zirconium nitrate, ammonium molybdate, and ammonium metavanadate.

[0020] Preferably, the Cu source in step (2) is at least one of copper nitrate, copper sulfate, basic copper sulfate, copper acetate, copper chloride, and copper carbonate.

[0021] Preferably, the solvent is any one of water, ethanol, and methanol.

[0022] The above catalyst is applied to the dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone, and the application method comprises the following steps:

[0023] S1, the catalyst is mixed and diluted with 40-60 mesh quartz sand, and then loaded into a fixed bed reactor, heated to 230-300℃ under a nitrogen atmosphere, and kept at a constant temperature for 0.5-2 h;

[0024] S2, the nitrogen is switched to a 2-20 vol% H2 / N2 mixed gas, and pretreated for 1-3 h;

[0025] S3, diethylene glycol is fed into the reactor, and the reacted liquid is fed into a collection tank under heat preservation conditions to prepare 1,4-dioxane-2-ketone.

[0026] Preferably, the gas flow rate of the mixed gas in step S2 is 10-50 mL / min.

[0027] Preferably, the mass space velocity of diethylene glycol in step S3 is 2.5-5 h -1 .

[0028] The present application provides a heteroatom modified SiO2 supported copper oxide catalyst, a preparation method and application thereof, and has the following advantages compared with the prior art:

[0029] The multi-valence heteroatom oxide modified mesoporous silica supported copper oxide catalyst provided by the application has excellent catalytic activity, the diethylene glycol conversion rate is > 99%, and the 1, 4-dioxane-2-ketone yield rate is > 98%; the catalyst has long cycle operation life, and the activity does not obviously decrease in the evaluation process of 500 h. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Nitrogen adsorption-desorption curves of the carrier SiO2 in the examples 1-6 and the comparative example 1 of the application;

[0031] Figure 2 TEM image of the catalyst 15wt%CuO x / 2 wt%CeO y -SiO2 in the example 3 of the application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the examples of the application more clear, the technical scheme in the examples of the application is described clearly and completely in combination with the examples of the application. Obviously, the described examples are part of the examples of the application, rather than all the examples of the application. Based on the examples in the application, all other examples obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0033] The SiO2 used in the following examples is spherical silica with a specific surface area of 80-600 m 2 / g and a pore size of 2-60 nm.

[0034] Example 1:

[0035] 1, Preparation of the catalyst 5wt%CuO x / 2wt%CeO y -SiO2:

[0036] (1) 100 g of SiO2 is immersed in 75 mL of an aqueous solution containing 8.2 g of cerium ammonium nitrate by using an equal-volume immersion method, ultrasonic dispersion is performed for 15 min, then the mixture is dried at 85℃ for 6 h; the obtained powder is fully ground and calcined at 600℃ for 4 h to obtain a Ce-modified SiO2 carrier, which is recorded as 2wt%CeO y -SiO2;

[0037] (2) 20 g of 2wt%CeO y -SiO2 is immersed in 15 mL of an aqueous solution containing 4.0 g of copper nitrate, ultrasonic dispersion is performed for 15 min, then the mixture is dried at 80℃ for 3 h; then the obtained powder is fully ground and calcined at 550℃ for 4 h to obtain the target catalyst.

[0038] 2. Catalytic dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone reaction:

[0039] (1) 5 g of 40-60 mesh 5wt% CuO x / 2 wt% CeO y -SiO2catalyst was mixed with an equal amount of 40-60 mesh quartz sand for dilution, slowly loaded into a fixed bed reactor, replaced with nitrogen three times, and then the reactor was heated to 250°C under nitrogen atmosphere, and kept at constant temperature for 0.5 h;

[0040] (2) Nitrogen was switched to 5 vol% H2 / N2mixed gas, pretreated for 1.5 h at a gas flow rate of 30 mL / min;

[0041] (3) Then, diethylene glycol was fed into the reactor at a mass space velocity of 2.5 h -1 , and the reaction liquid was kept at 60°C and entered the collection tank, and the products were analyzed by gas chromatograph, and the reaction results are shown in Table 1.

[0042] Example 2:

[0043] 1. Preparation of catalyst 10wt% CuO x / 4wt% CeO y -SiO2:

[0044] (1) 100 g of SiO2was impregnated in 75 mL of aqueous solution containing 16.4 g of cerium nitrate ammonium by equal volume impregnation method, ultrasonic dispersion for 15 min, and then the mixture was dried at 85°C for 6 h; the obtained powder was fully ground and calcined at 600°C for 4 h to obtain Ce modified SiO2support, marked as 4wt% CeO y -SiO2;

[0045] (2) 20 g of 2wt% CeO y -SiO2was impregnated in 15 mL of aqueous solution containing 8.0 g of copper nitrate, ultrasonic dispersion for 15 min, and then the mixture was dried at 80°C for 3 h; then the obtained powder was fully ground and calcined at 550°C for 4 h to obtain the target catalyst, marked as 10wt% CuO x / 4wt% CeO y -SiO2;

[0046] 2. Catalytic dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone reaction:

[0047] (1) 5 g of 40-60 mesh 10wt% CuO x / 4wt% CeO y- SiO2catalyst mixed with equal mass of 40-60 mesh quartz sand was slowly loaded into a fixed bed reactor, replaced with nitrogen three times, and then the reactor was heated to 250°C under nitrogen atmosphere, and kept constant for 0.5 h;

[0048] (2) Nitrogen was switched to 5 vol% H2 / N2mixed gas, and pretreated for 1.5 h at a gas flow rate of 30 mL / min;

[0049] (3) Then, diethylene glycol was fed into the reactor at a mass space velocity of 2.5 h -1 -1, and the reaction liquid was kept at 60°C and then entered into a collection tank. The products were analyzed by a gas chromatograph, and the reaction results are shown in Table 1.

[0050] Example 3:

[0051] 1. Preparation of catalyst 15wt% CuO x / 2wt% CeO y -SiO2:

[0052] (1) 100 g SiO2was impregnated in 75 mL aqueous solution containing 8.2 g cerium ammonium nitrate by equal volume impregnation method, ultrasonic dispersion for 15 min, and then the mixture was dried at 85°C for 6 h. The obtained powder was fully ground and calcined at 600°C for 4 h to obtain Ce-modified SiO2support, noted as 2wt% CeO y -SiO2;

[0053] (2) 20 g 2wt% CeO y -SiO2was impregnated in 15 mL aqueous solution containing 12.0 g copper nitrate, ultrasonic dispersion for 15 min, and then the mixture was dried at 80°C for 3 h. The obtained powder was fully ground and calcined at 550°C for 4 h to obtain the target catalyst, noted as 15wt% CuO x / 2wt% CeO y -SiO2;

[0054] 2. Catalytic dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone

[0055] (1) 5 g 40-60 mesh 15wt% CuO x / 2wt% CeO y -SiO2catalyst was mixed with equal mass of 40-60 mesh quartz sand, slowly loaded into a fixed bed reactor, replaced with nitrogen three times, and then the reactor was heated to 250°C under nitrogen atmosphere, and kept constant for 0.5 h;

[0056] (2) Switch nitrogen to 5 vol% H2 / N2mixed gas, pretreatment for 1.5 h at a gas flow rate of 30 mL / min;

[0057] (3) Then, diethylene glycol is fed into the reactor at a mass space velocity of 2.5 h -1 -1, and the reaction solution is kept at 60°C and then enters the collection tank. The product is analyzed by a gas chromatograph, and the reaction results are shown in Table 1.

[0058] Example 4:

[0059] 1. Preparation of catalyst 20 wt% CuO x / 2 wt% CeO y -SiO2:

[0060] (1) 100 g SiO2is impregnated in 75 mL aqueous solution containing 8.2 g cerium ammonium nitrate by using an equal volume impregnation method, ultrasonic dispersion is performed for 15 min, and then the mixture is dried at 85°C for 6 h. The obtained powder is fully ground and calcined at 600°C for 4 h to obtain a Ce-modified SiO2carrier, which is recorded as 2 wt% CeO y -SiO2.

[0061] (2) 20 g 2 wt% CeO x -SiO2is impregnated in 15 mL aqueous solution containing 16.0 g copper nitrate, ultrasonic dispersion is performed for 15 min, and then the mixture is dried at 80°C for 3 h. The obtained powder is fully ground and calcined at 550°C for 4 h to obtain the target catalyst, which is recorded as 20 wt% CuO y / 2 wt% CeO x -SiO2.

[0062] 2. Catalytic dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone:

[0063] (1) 5 g 20 wt% CuO y / 2 wt% CeO -1 -SiO2catalyst with a particle size of 40-60 mesh is mixed and diluted with an equal mass of 40-60 mesh quartz sand, slowly loaded into a fixed bed reactor, replaced with nitrogen three times, and then the reactor is heated to 250°C under a nitrogen atmosphere, and kept at a constant temperature for 0.5 h;

[0064] (2) Switch nitrogen to 5 vol% H2 / N2mixed gas, pretreatment for 1.5 h at a gas flow rate of 30 mL / min;

[0065] (3) Diethylene glycol is fed into the reactor at a mass space velocity of 2.5 h -1The reaction liquid was kept at 60°C and then entered a collection tank, and the products were analyzed by a gas chromatograph. The reaction results are shown in Table 1.

[0066] Example 5:

[0067] 1. Catalyst 15wt%CuO x / 2wt%ZrO y Preparation of 2wt%ZrO

[0068] (1) 100 g of SiO2 was impregnated in 75 mL of an aqueous solution containing 10.1 g of zirconium nitrate by using an equal-volume impregnation method, ultrasonic dispersion was performed for 15 min, and then the mixture was dried at 85°C for 6 h; the obtained powder was fully ground and calcined at 600°C for 4 h to obtain a Zr-modified SiO2 carrier, which was recorded as 2wt%ZrO y -SiO2.

[0069] (2) 20 g of 2wt%ZrO x -SiO2 was impregnated in 15 mL of an aqueous solution containing 12.0 g of copper nitrate, ultrasonic dispersion was performed for 15 min, and then the mixture was dried at 80°C for 3 h; the obtained powder was fully ground and calcined at 550°C for 4 h to obtain the target catalyst, which was recorded as 15wt%CuO y / 2wt%ZrO x -SiO2.

[0070] 2. Catalytic dehydrogenation and cyclization of diethylene glycol to prepare 1,4-dioxane-2-ketone:

[0071] (1) 5 g of 15wt%CuO y / 2wt%ZrO -1 -SiO2 catalyst with a particle size of 40-60 mesh was mixed with an equal amount of 40-60 mesh quartz sand for dilution, and then slowly loaded into a fixed-bed reactor, which was replaced with nitrogen three times, and then heated to 250°C under a nitrogen atmosphere, and kept at a constant temperature for 0.5 h;

[0072] S2, nitrogen was switched to a 5 vol% H2 / N2 mixed gas, and pretreated at a flow rate of 30 mL / min for 1.5 h;

[0073] S3, diethylene glycol was fed into the reactor at a mass space velocity of 2.5 h -1 The reaction liquid was kept at 60°C and then entered a collection tank, and the products were analyzed by a gas chromatograph. The reaction results are shown in Table 1.

[0074] Example 6:

[0075] According to the above-mentioned Example 5, a catalyst 15wt%CuO x / 2wt%CeO y -SiO2;

[0076] 15wt%CuO x / 2wt%CeO y -SiO2catalyst in the reaction of catalytic dehydrogenation and cyclization of diethylene glycol to 1,4-dioxane-2-one was evaluated under different reaction temperature and different space velocity conditions:

[0077] (1) 5 g of 15wt%CuO x / 2wt%CeO y -SiO2catalyst was mixed with equal mass of 40-60 mesh quartz sand for dilution, and then slowly loaded into a fixed bed reactor. After three times of replacement with nitrogen, the reactor was heated to 220°C, 300°C or 320°C under nitrogen atmosphere, and kept at constant temperature for 0.5 h;

[0078] S2, switch nitrogen to 5 vol%H2 / N2mixed gas, pretreatment for 1.5 h at a flow rate of 30 mL / min;

[0079] S3, diethylene glycol was fed into the reactor at a mass space velocity of 1 h -1 , 5 h -1 , 10 h -1 or 15 h -1 , and the reaction liquid was kept at 60°C and then entered into a collection tank. The products were analyzed by gas chromatograph, and the reaction results are shown in Table 2.

[0080] Comparative Example 1:

[0081] 1, preparation of catalyst 15wt%CuO x / SiO2:

[0082] 20 g of SiO2was immersed in 15 mL of aqueous solution containing 12 g of copper nitrate by equal volume impregnation method, and ultrasonic dispersion was carried out for 15 min. Then the mixture was dried at 85°C for 6 h. The obtained powder was fully ground and calcined at 550°C for 4 h to obtain the target catalyst, which is denoted as 15wt%CuO x / SiO2;

[0083] 2, catalytic dehydrogenation and cyclization of diethylene glycol to 1,4-dioxane-2-one

[0084] S1, 5 g of 15wt%CuO x / SiO2catalyst was mixed with equal mass of 40-60 mesh quartz sand for dilution, and then slowly loaded into a fixed bed reactor. After three times of replacement with nitrogen, the reactor was heated to 250°C under nitrogen atmosphere, and kept at constant temperature for 0.5 h;

[0085] S2, then, switch nitrogen to 5 vol% H2 / N2 mixed gas, pretreat for 1.5 h at a gas flow rate of 30 mL / min;

[0086] S3, then, put diethylene glycol into the reactor at a mass space velocity of 2.5 h -1 -1, and the reaction solution is kept at 60℃ and then enters the collection tank, and the product is analyzed by a gas chromatograph, and the reaction results are shown in Table 1.

[0087] Detection:

[0088] 1, detect the reaction data of diethylene glycol catalytic dehydrogenation and cyclization to prepare 1,4-dioxane-2-ketone in Examples 1-5 and Comparative Example 1, and the specific results are shown in Table 1 below:

[0089]

[0090] In the above table, X DEG is the conversion rate of diethylene glycol, and Y PDO is the yield of 1,4-dioxane-2-ketone.

[0091] As can be seen from Table 1, after the active species of copper oxide supported on SiO2 modified by Ce or Zr heteroatoms, the long-term running life of the catalyst can be significantly improved, so that it can be increased from 100 h to 500 h without deactivation. When the loading amount of the active species is small, the stability of the catalyst will be significantly reduced.

[0092] 2, detect the reaction data of diethylene glycol catalytic dehydrogenation and cyclization to prepare 1,4-dioxane-2-ketone in Example 6, and the specific results are shown in Table 2 below:

[0093]

[0094] In the above table, X DEG is the conversion rate of diethylene glycol, and Y PDO is the yield of 1,4-dioxane-2-ketone.

[0095] As can be seen from Table 2, the conversion rate of diethylene glycol and the yield of 1,4-dioxane-2-ketone are closely related to the reaction conditions. Under the conditions of 250℃ and a space velocity of 2.5-5 h -1 , the conversion rate of diethylene glycol can be >99%, and the yield of 1,4-dioxane-2-ketone can be >98%.

[0096] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. The application of a heteroatom-modified SiO2-supported copper oxide catalyst in the dehydrogenation cyclization of diethylene glycol to produce 1,4-dioxane-2-one, characterized in that, The catalyst is composed of the following components by mass percentage: 1%-5% heteroatoms, 15% active component, and the balance being SiO2. The heteroatoms are one or more of Ce, Zr, Mo, and V, and the active component is copper oxide. The catalyst uses heteroatom-modified SiO2 as a support. The catalyst is prepared by the following steps: (1) SiO2 is immersed in an equal volume of solvent containing heteroatom metal precursor, ultrasonically dispersed for 10-30 min, and then dried at 70-90℃ for 4-8 h; the product is thoroughly ground and then calcined at 500-700℃ for 3-8 h to obtain heteroatom modified SiO2, denoted as M-SiO2. (2) M-SiO2 is impregnated in a solvent containing Cu source, ultrasonically dispersed for 10-30 min, and then dried at 70-90℃ for 2-6 h; then the resulting powder is thoroughly ground and calcined at 400-700℃ for 2-8 h to obtain atomically modified SiO2-supported CuO. x Catalyst raw material, denoted as CuO x / M-SiO2; (3) The above CuO x / M-SiO2 is compressed into tablets, granulated, and sieved to 40-60 mesh to obtain the catalyst.

2. The application according to claim 1, characterized in that: The SiO2 has a specific surface area of ​​300-600 m². 2 / g, spherical silica with pore size of 5-30 nm.

3. The application according to claim 1, characterized in that: In step (1), the heteroatom metal precursor is any one or more of cerium ammonium nitrate, zirconium nitrate, ammonium molybdate, and ammonium metavanadate.

4. The application according to claim 1, characterized in that: In step (2), the Cu source is at least one of copper nitrate, copper sulfate, basic copper sulfate, copper acetate, copper chloride, and copper carbonate.

5. The application according to claim 1, characterized in that, The method of application includes the following steps: S1. The catalyst is mixed and diluted with 40-60 mesh quartz sand and then loaded into a fixed-bed reactor. The temperature is raised to 230-300℃ under a nitrogen atmosphere and held at that temperature for 0.5-2 h. S2. Switch the nitrogen gas to a 2-20 vol% H2 / N2 mixture and pretreat for 1-3 hours. S3 and diethylene glycol enter the reactor, and the reacted liquid enters the collection tank under heat preservation conditions to prepare 1,4-dioxane-2-one.

6. The application according to claim 5, characterized in that: In step S2, the gas flow rate of the mixed gas is 10-50 mL / min.

7. The application according to claim 5, characterized in that: In step S3, the mass hourly space velocity (MSV) of diethylene glycol is 2.5-5 h⁻¹. -1 .

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