Composite metal oxide, preparation method and application thereof, and dehydrogenation method of 1, 4-butanediol

Abstract

The invention relates to the technical field of catalysts, and discloses a composite metal oxide, a preparation method and application thereof, and a dehydrogenation method of 1, 4-butanediol. The composite metal oxide comprises a copper element, a zirconium element and a metal M element, the metal M element is selected from at least one of a zinc element, an aluminum element, a manganese element, a titanium element and a cerium element, the zirconium oxide comprises ZrO2 and Zr3O1-x, and the value of x is greater than 0 and less than 1. The composite metal oxide provided by the invention is particularly suitable for the dehydrogenation reaction of 1, 4-butanediol, when the composite metal oxide is applied to the dehydrogenation reaction of 1, 4-butanediol, the reaction temperature can be reduced, the catalyst is high in activity, good in stability and high in target product selectivity, and in addition, the composite metal oxide provided by the invention does not contain Cr, and is environment-friendly and pollution-free.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a composite metal oxide, its preparation method and application, and a method for the dehydrogenation of 1,4-butanediol. Background Technology

[0002] γ-Butyrolactone (GBL), also known as 4-hydroxybutyric acid lactone, is a five-membered heterocyclic compound. It is a colorless liquid with an acetone-like odor, characterized by a high boiling point and high solubility. It exhibits good reactivity, high conductivity, good stability, and safe use. As an important organic solvent, γ-butyrolactone is widely used in the petroleum industry, pharmaceuticals, synthetic fibers, synthetic resins, pesticides, and many other fields. As an important raw material for fine and organic chemicals, γ-butyrolactone is mainly used in the synthesis of pyrrolidone, N-methylpyrrolidone, vinylpyrrolidone, and other products.

[0003] Based on the classification of raw materials, methods for synthesizing γ-butyrolactone include the furfural method, the maleic anhydride hydrogenation method, and the 1,4-butanediol dehydrogenation method. The main byproducts of the 1,4-butanediol dehydrogenation reaction are tetrahydrofuran (THF) and a small amount of butanol (BOL). The composition is simple, the products are easily separated, and the synthesized γ-butyrolactone is of high quality, meeting the high requirements for γ-butyrolactone in pharmaceutical raw materials and battery electrolytes. Therefore, the 1,4-butanediol dehydrogenation method has become the main method for synthesizing γ-butyrolactone.

[0004] Currently, the main catalysts for the preparation of γ-butyrolactone via the 1,4-butanediol dehydrogenation method are copper-chromium (Cu-Cr) catalysts. However, the application of Cu-Cr catalysts in the 1,4-butanediol dehydrogenation reaction suffers from problems such as low γ-butyrolactone yield and Cr pollution. In recent years, with increasing emphasis on environmental protection, Cu-Zn catalysts, previously used as hydrogenation catalysts, have become a research hotspot for 1,4-butanediol dehydrogenation catalysts, attracting growing attention.

[0005] CN112371130A discloses a dehydrogenation catalyst and its preparation method. The dehydrogenation catalyst is composed of CuO, ZnO, and ZrO2 in a molar ratio of 5:(1-5):(0.5-4). The specific steps of the preparation method are as follows: 1) Dissolve soluble salts of Cu, Zn, and Zr in water according to the proportions of Cu, Zn, and Zr in the dehydrogenation catalyst to obtain a mixed solution; 2) Mix the mixed solution with a precipitant solution and perform co-precipitation. After the co-precipitation reaction is completed, the mixture is successively aged, filtered, and washed to obtain a precipitate; 3) Dry the precipitate and calcine it at 300-400℃ for 3-5 hours to obtain the dehydrogenation catalyst.

[0006] However, compared with Cr-containing catalysts, existing Cr-free 1,4-butanediol dehydrogenation catalysts generally suffer from the drawback of failing to balance target product selectivity and catalyst stability. Although the problem has been improved by adding various metal promoters, the stability is still insufficient to meet the requirements of long-term operation compared with traditional copper-chromium catalysts. Therefore, it is necessary to develop a Cr-free 1,4-butanediol dehydrogenation catalyst that balances high catalytic activity, good selectivity, and good catalyst stability. Summary of the Invention

[0007] To address the aforementioned deficiencies in existing technologies, this invention provides a composite metal oxide, its preparation method and application, as well as a method for the dehydrogenation of 1,4-butanediol. The composite metal oxide provided by this invention, when used as a catalyst in dehydrogenation reactions, exhibits advantages such as high catalytic activity, good stability, and high selectivity for the target product.

[0008] The first aspect of this invention provides a composite metal oxide comprising copper, zirconium, and a metallic element M, wherein the metallic element M is selected from at least one of zinc, aluminum, manganese, titanium, and cerium, and the zirconium oxide comprises ZrO2 and Zr3O. 1-x The value of x is greater than 0 and less than 1.

[0009] Preferably, ZrO2 and Zr3O 1-x The molar ratio is 4-7:1, preferably 5-6:1.

[0010] Preferably, the molar ratio of copper, zirconium, and metallic M is 3:(1.1-3):(0.5-2), more preferably 3:(1.8-2.3):(0.8-1.2).

[0011] Preferably, the copper dispersion in the composite metal oxide is 50%-80%, more preferably 55%-75%.

[0012] A second aspect of this invention provides a method for preparing a composite metal oxide, the method comprising the following steps:

[0013] (1) In the presence of a nonionic surfactant, a copper source, a zirconium source, an M source and a precipitant are subjected to a co-precipitation reaction to obtain the reaction product; M is selected from at least one of zinc, aluminum, manganese, titanium and cerium;

[0014] (2) The reaction product described in step (1) is pre-calcined and calcined at a temperature of 150-250°C.

[0015] The amounts of copper source, zirconium source, and M source are such that the molar ratio of copper, zirconium, and metallic M in the prepared composite metal oxide is 3:(1.1-3):(0.5-2), preferably 3:(1.8-2.3):(0.8-1.2).

[0016] The third aspect of this invention provides the application of the composite metal oxide described in the first aspect or the composite metal oxide prepared by the preparation method described in the second aspect in dehydrogenation reactions.

[0017] The fourth aspect of the present invention provides a method for the dehydrogenation reaction of 1,4-butanediol, the method comprising: contacting 1,4-butanediol with a dehydrogenation catalyst in the presence of hydrogen and under dehydrogenation reaction conditions, wherein the dehydrogenation catalyst comprises the composite metal oxide described in the first aspect or the composite metal oxide prepared by the preparation method described in the second aspect.

[0018] Compared with the prior art, the beneficial effects of the present invention mainly include:

[0019] (1) In conventional copper-zirconium dehydrogenation catalysts, zirconium oxide exists in the form of ZrO2. The inventors discovered that introducing an appropriate amount of zirconium suboxide (Zr3O2) into the copper-zirconium composite metal oxide catalyst... 1-x This catalyst can effectively adjust and extend the optimal temperature range for the reaction, especially by lowering the reaction temperature. It also significantly improves catalytic activity and selectivity for the target product, while exhibiting good stability after long-term use. Further optimization of the ratio of copper, zirconium, and metallic M can further enhance the catalyst's performance. For example, at a reaction temperature of 190℃, after a long reaction period of 600 hours, the conversion rate can still reach 99.7%, the selectivity 98.7%, and the yield 98.4%.

[0020] (2) The composite metal oxide provided by the present invention is particularly suitable for the dehydrogenation reaction of 1,4-butanediol. When applied to the dehydrogenation reaction of 1,4-butanediol, it can not only reduce the reaction temperature, but also has the advantages of high activity, good stability and high selectivity of target product.

[0021] (3) The composite metal oxide provided by the present invention can be Cr-free, environmentally friendly and pollution-free. Attached Figure Description

[0022] Figure 1 The image shows the XRD pattern of the composite metal oxide obtained in Example 1.

[0023] Figure 2 Here is a SEM image of the composite metal oxide obtained in Example 1;

[0024] Figure 3The XRD pattern of the composite metal oxide obtained in Comparative Example 1 is shown.

[0025] Figure 4 The XRD pattern of the composite metal oxide obtained in Comparative Example 3 is shown.

[0026] Figure 5 The image shows the XRD pattern of the composite metal oxide obtained in Comparative Example 4. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] The first aspect of this invention provides a composite metal oxide comprising copper, zirconium, and a metallic element M, wherein the metallic element M is selected from at least one of zinc, aluminum, manganese, titanium, and cerium, and the zirconium oxide comprises ZrO2 and Zr3O. 1-x The value of x is greater than 0 and less than 1.

[0029] In this invention, Zr3O 1-x It is a type of zirconium suboxide, Zr3O 1-x The presence of [the substance] can be confirmed by XRD characterization and comparison with the standard card JCPDS#21-1498. Specifically, the characteristic peak at 2θ of 29.3 ± 0.3° is attributed to Zr3O. 1-x The characteristic peaks are unaffected by other components.

[0030] In this invention, "Zr3O" 1-x The value of "x" in "Zr3O" is not specifically limited; it is only used to represent one crystal phase of Zr. 1-x The existence of “ can be determined based on the XRD above.

[0031] According to a preferred embodiment of the present invention, X-ray diffraction analysis revealed that the composite metal oxide exhibited a diffraction peak at 2θ of 29.3 ± 0.3°, preferably at 29.3 ± 0.3°, 36.2 ± 0.3°, 56.6 ± 0.3°, and 68.0 ± 0.3°. Specifically, corresponding to standard card JCPDS#21-1498, the peak at 29.3 ± 0.3° corresponds to Zr3O. 1-x The (104) crystal plane diffraction peak at 36.2±0.3° corresponds to Zr3O. 1-xThe (113) crystal plane diffraction peak at 56.6±0.3° corresponds to Zr3O. 1-x The (300) diffraction peak at 68.0±0.3° corresponds to Zr3O. 1-x The (306) crystal plane diffraction peak.

[0032] This invention provides a composite metal oxide comprising copper, zirconium, and metal M, wherein metal M is selected from at least one of zinc, aluminum, manganese, titanium, and cerium. X-ray diffraction analysis reveals that the composite metal oxide exhibits a diffraction peak at 2θ of 29.3 ± 0.3°, preferably at 29.3 ± 0.3°, 36.2 ± 0.3°, 56.6 ± 0.3°, and 68.0 ± 0.3°.

[0033] According to the present invention, preferably, ZrO2 and Zr3O 1-x The molar ratio is 4-7:1, for example 4:1, 4.2:1, 4.5:1, 4.8:1, 5:1, 5.2:1, 5.5:1, 5.8:1, 6:1, 6.2:1, 6.5:1, 6.8:1, or 7:1, preferably 5-6:1. This preferred embodiment is more advantageous in improving the catalytic activity, stability, and selectivity of the composite metal oxide as a dehydrogenation catalyst.

[0034] In this invention, ZrO2 and Zr3O 1-x The molar ratio of ZrO2 and Zr3O was obtained by XRD testing. 1-x The molar ratio is shown in the XRD pattern. The integral peak area of ​​the characteristic peak (ZrO2(101)) at 2θ of 30.4±0.3° is equal to that of the characteristic peak (Zr3O) at 2θ of 29.3±0.3°. 1-x (104) The ratio of the area of ​​the integral peak.

[0035] In this invention, X-ray diffraction (XRD) tests were performed using a Rigaku D / max2500 X-ray diffractometer with a Cu target, Kα radiation source, 80 mA current, and a wide-angle scanning range of 5°–70°. Peak areas were obtained by integration using Jade software.

[0036] In this invention, ZrO2 and Zr3O 1-x The molar ratio is the area of ​​the integral peak of the characteristic peak (ZrO2(101)) at 2θ of 30.4±0.3° and the area of ​​the characteristic peak (Zr3O) at 2θ of 29.3±0.3° in the XRD spectrum. 1-x (104) The ratio of the area of ​​the integral peak.

[0037] According to the present invention, preferably, the molar ratio of copper to zirconium is 3:(1.1-3), for example 3:1, 3:1.2, 3:1.5, 3:1.8, 3:2, 3:2.2, 3:2.5, 3:2.8 or 3:3, preferably 3:(1.3-2.7), and more preferably 3:(1.8-2.3).

[0038] According to the present invention, preferably, the molar ratio of copper to metallic M is 3:(0.5-2), for example 3:0.5, 3:0.7, 3:1, 3:1.2, 3:1.5, 3:1.8 or 3:2, preferably 3:(0.5-1.9), more preferably 3:(0.5-1.7), and even more preferably 3:(0.8-1.2).

[0039] According to a preferred embodiment of the present invention, the molar ratio of copper, zirconium and metallic M is 3:(1.1-3):(0.5-2), preferably 3:(1.3-2.7):(0.5-1.7), and more preferably 3:(1.8-2.3):(0.8-1.2).

[0040] The inventors of this invention discovered through research that introducing an appropriate amount of zirconium suboxide (Zr3O) into a copper-zirconium composite metal oxide catalyst... 1-x Furthermore, by optimizing the ratio of copper, zirconium, and metallic M, the optimal temperature range of the catalyst in the reaction can be adjusted and expanded more effectively, especially by reducing the reaction temperature, while also significantly improving catalytic activity, stability, and selectivity of the target product.

[0041] In this invention, the molar ratio of copper, zirconium, and metallic M in the composite metal oxide was obtained by X-ray fluorescence spectroscopy (XRF). Specifically, a ZSX Primus IV X-ray fluorescence spectrometer was used for the test, with an X-ray tube operating power of 4kW, an end-window rhodium target X-ray tube, a maximum operating voltage of 60kV, a maximum operating current of 150mA, and a Be window film thickness of 30 micrometers.

[0042] In this invention, the objective can be achieved by combining copper and zirconium with at least one of zinc, aluminum, manganese, titanium, and cerium. Preferably, element M is selected from at least one of zinc, aluminum, and manganese. This preferred embodiment is more conducive to improving the catalytic activity and stability of the composite metal oxide and the selectivity of the target product.

[0043] According to the present invention, preferably, the copper dispersion in the composite metal oxide is 50%-80%, more preferably 55%-75%, for example 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, or 75%. The composite metal oxide provided by the present invention exhibits a high copper dispersion, whereas in existing composite metal oxide catalysts, the copper dispersion is generally no higher than 45%.

[0044] In this invention, the dispersion of copper in the composite metal oxide can be understood as the ratio between the hydrogen consumption of surface copper atoms and the hydrogen consumption of all copper atoms, specifically determined by the N2O / H2-TPR method. The specific testing method includes: For the first TPR experiment, 50 mg of sample is taken and reduced in a 10 vol% H2 / N2 mixture at a flow rate of 30 mL / min to 450 °C for 2 h at a heating rate of 10 °C / min. The hydrogen consumption in the first TPR is taken as the total hydrogen consumption of copper atoms. Then, the reactor is purged to 50 °C with He gas. The surface copper atoms are oxidized to Cu2O using 20 vol% N2O / N2 at a flow rate of 30 mL / min at 50 °C for 0.5 h. The reactor is then flushed with He gas to remove the oxidant. Finally, a second TPR experiment is conducted in a 10 vol% H2 / N2 mixture at a flow rate of 30 mL / min, under the same conditions as the first TPR experiment. The hydrogen consumption in the second TPR is taken as the hydrogen consumption of surface copper atoms. The ratio of twice the hydrogen consumption of surface copper atoms to the total hydrogen consumption of all copper atoms is the dispersion of Cu.

[0045] According to the present invention, preferably, the specific surface area of ​​the composite metal oxide is 70-100 m². 2 / g, preferably 75-100mg 2 / g, more preferably 80-100m 2 / g. The composite metal oxide provided by this invention has a higher specific surface area, and therefore exhibits higher catalytic dehydrogenation performance when used as a dehydrogenation catalyst. In this invention, the specific surface area is obtained by nitrogen isothermal adsorption-desorption method, specifically measured using a Micromeritics ASAP-2420 physical adsorption instrument.

[0046] According to a preferred embodiment of the present invention, the composite metal oxide does not contain Cr. The composite metal oxide provided by the present invention achieves high dehydrogenation performance without the addition of metallic Cr. Compared to existing copper-chromium (Cu-Cr) catalysts, it is more environmentally friendly and pollution-free.

[0047] The present invention does not impose any particular limitation on the preparation method of the composite metal oxide, as long as the composite metal oxide having the above composition and structure can be prepared.

[0048] A second aspect of this invention provides a method for preparing a composite metal oxide, the method comprising the following steps:

[0049] (1) In the presence of a nonionic surfactant, a copper source, a zirconium source, an M source and a precipitant are subjected to a co-precipitation reaction to obtain the reaction product; M is selected from at least one of zinc, aluminum, manganese, titanium and cerium;

[0050] (2) The reaction product described in step (1) is pre-calcined and calcined at a temperature of 150-250°C.

[0051] The amounts of copper source, zirconium source, and M source are such that the molar ratio of copper, zirconium, and metal M in the prepared composite metal oxide is 3:(1.1-3):(0.5-2).

[0052] The present invention allows for a wide range of choices regarding the types of nonionic surfactants used in step (1), as long as the composite metal oxide described in the first aspect can be prepared by the method provided by the present invention. Preferably, the nonionic surfactant is at least one of polyether-type nonionic surfactants, polyoxyethylene-type nonionic surfactants, alkyloxyamine-type nonionic surfactants, and alkanolamide-type nonionic surfactants, with polyether-type nonionic surfactants being the most preferred. This preferred embodiment is more advantageous in improving the catalytic activity and stability of the prepared composite metal oxide as a dehydrogenation catalyst, as well as the selectivity of the target product.

[0053] This invention allows for a wide range of choices of polyoxyethylene-type nonionic surfactants, such as AEO (polyoxyethylene fatty alcohol ether), TX (alkylphenol polyoxyethylene ether), Tween (polyoxyethylene sorbitan ester), etc.

[0054] This invention allows for a wide range of choices for alkyloxyamine type nonionic surfactants, such as laurylamine oxides like OB-2 and OA-12.

[0055] This invention allows for a wide range of choices of alkanolamide-type nonionic surfactants, such as DEA (cocoamide) and lauroyl diethanolamine.

[0056] In a preferred embodiment, the polyether-type nonionic surfactant is selected from at least one of PE (isomeric alcohol ether), APEG (allyl polyethylene glycol), F127 (polyoxyethylene polyoxypropylene ether), and P123 (polyethylene oxide-polyoxypropylene-polyethylene oxide triblock copolymer), preferably F127 and / or P123.

[0057] The present invention does not specifically limit the source of the nonionic surfactants such as F127 and / or P123, which can be obtained commercially or prepared by the manufacturer.

[0058] According to the present invention, preferably, the amount of the nonionic surfactant added is 0.5wt%-2.2wt% of the amount of copper source added, more preferably 1wt%-2wt%. This preferred embodiment is more advantageous in improving the dehydrogenation reaction performance of the prepared composite metal oxide as a dehydrogenation catalyst.

[0059] This invention allows for a wide range of selection for copper, zirconium, and M sources, as long as soluble copper, zirconium, and M substances can be provided. Preferably, in step (1), the copper, zirconium, and M sources are each independently selected from soluble salts of metals. For example, the copper and M sources are each independently selected from, but are not limited to, nitrates. The zirconium source can be at least one of zirconium nitrate, zirconium chloride, and zirconium oxychloride, preferably zirconium oxychloride. Using zirconium oxychloride as the zirconium source is more beneficial for improving the dehydrogenation reaction performance of the prepared composite metal oxide as a dehydrogenation catalyst.

[0060] The copper source, zirconium source, and M source can all be selected to contain water of crystallization.

[0061] The present invention allows for a wide range of selection for the amounts of the copper source, zirconium source, and M source. The amounts of the copper source, zirconium source, and M source are such that the molar ratio of copper, zirconium, and metal M in the prepared composite metal oxide is 3:(1.1-3):(0.5-2), preferably 3:(1.3-2.7):(0.5-1.7), more preferably 3:(1.8-2.3):(0.8-1.2). Other optional ranges can be found in the first aspect of the present invention, which will not be elaborated further here.

[0062] Those skilled in the art will know how to select the amount of copper source, zirconium source, M source and precipitant based on the above disclosure.

[0063] According to the present invention, preferably, the coprecipitation reaction in step (1) further includes the introduction of a solvent. The present invention allows for a wide range of choices regarding the type and amount of the solvent, as long as it can provide a mixed environment for the copper source, zirconium source, M source, nonionic surfactant, and precipitant. For example, the solvent can be water.

[0064] The present invention does not particularly limit the specific implementation of the coprecipitation reaction described in step (1). It can be a co-current coprecipitation of a solution containing a copper source, a zirconium source, and an M source with a precipitant; it can be a direct addition coprecipitation by first adding the solution containing the copper source, zirconium source, and M source and then adding the precipitant; or it can be a reverse addition coprecipitation by first adding the precipitant and then adding the solution containing the copper source, zirconium source, and M source. The present invention does not particularly limit the method of adding the nonionic surfactant; it can be added to the solution containing the copper source, zirconium source, and M source, or it can be added to the substrate for the coprecipitation reaction. Preferably, a mixture containing a copper source, a zirconium source, an M source, and a nonionic surfactant is provided, and then the mixture is coprecipitated with a precipitant.

[0065] According to a preferred embodiment of the present invention, step (1) includes providing a mixture containing a copper source, a zirconium source, an M source, and a nonionic surfactant, and then co-precipitating the mixture with a precipitant. Preferably, the mixture in step (1) also contains a solvent. More preferably, the amount of solvent added is such that the copper ion concentration in the mixture is 1.4-1.6 mol / L. The solvent can be added all at once or in stages.

[0066] The present invention does not particularly limit the conditions for providing the mixture, as long as it can achieve uniform mixing. Preferably, the mixing temperature of the mixture is 25-60°C.

[0067] The present invention does not particularly limit the specific order of mixing, as long as the mixture can be provided. Preferably, the copper source, zirconium source, and M source are first mixed with the solvent to dissolve the copper source, zirconium source, and M source, and then a nonionic surfactant is added and heated to the mixing temperature. The dissolution is preferably carried out under stirring conditions, and the stirring speed can be 100-1000 r / min.

[0068] The present invention does not particularly limit the type of precipitant in step (1), and can use conventional choices in the art. Preferably, the precipitant is an alkali. According to a preferred embodiment of the present invention, the precipitant in step (1) is selected from at least one of NaOH, Na2CO3, NaHCO3, NH4HCO3 and ammonia.

[0069] The precipitant of the present invention is preferably provided in the form of a precipitant solution. The concentration range of the precipitant solution is relatively wide, with the selection based on what is more conducive to the precipitation reaction. Preferably, when the precipitant is at least one of NaOH, Na2CO3, NaHCO3, and NH4HCO3, the concentration of the precipitant solution is 0.5-2 mol / L; when the precipitant is ammonia, the concentration of the precipitant solution (ammonia water) is 5wt%-15wt%.

[0070] Preferably, in step (1), the coprecipitation is a co-current precipitation.

[0071] According to a preferred embodiment of the present invention, in step (1), the conditions for the coprecipitation reaction include: a reaction temperature of 40-80°C, a reaction time of 10-60 min, and a pH value of 7.5-10 in the reaction system; more preferably, the reaction temperature is 50-70°C, the reaction time is 20-30 min, and the pH value of the reaction system is 8-9.

[0072] In this invention, the reaction time refers to the time of the parallel feeding process.

[0073] According to a preferred embodiment of the present invention, the method further includes aging the reaction product obtained in step (1) and then performing step (2).

[0074] Preferably, the aging conditions include a temperature of 10-80℃ and an aging time of 10-20 hours. There are no particular limitations on the aging method; it can be either stirring or standing.

[0075] According to a preferred embodiment of the present invention, the aging conditions include: first aging at 40-80°C (preferably the co-precipitation reaction temperature) under stirring for 10-60 min, preferably 20-30 min; then aging at 10-40°C under static conditions for 10-16 h, preferably 14-15 h. This preferred embodiment is more conducive to more complete metal precipitation and further ensures the stability of the product's crystal structure.

[0076] According to the present invention, it is preferable to further include washing the product aged in step (1). The washing can be performed using conventional techniques in the art, and the washing agent can be water (e.g., deionized water).

[0077] According to the present invention, prior to the pre-calcination in step (2), the reaction product described in step (1) is further dried. Preferably, the drying conditions include a temperature of 60-90°C and a time of 8-24 hours; more preferably, a temperature of 75-80°C and a time of 12-16 hours.

[0078] According to a preferred embodiment of the present invention, in step (2), the pre-calcination temperature is 150-220°C, for example, 150°C, 180°C, 200°C or 220°C.

[0079] According to a preferred embodiment of the present invention, in step (2), the pre-calcination time is 1-6 hours, preferably 1-4 hours.

[0080] The pre-calcination conditions described in the preferred embodiments above are more conducive to preparing composite metal oxides with better dehydrogenation performance.

[0081] According to a preferred embodiment of the present invention, in step (2), the calcination conditions include: a temperature of 300-500℃ and a time of 1-8h, preferably a temperature of 300-450℃ and a time of 2-4h, for example, the temperature is 300℃, 330℃, 350℃, 380℃, 400℃, 430℃ or 450℃, more preferably 390-430℃.

[0082] A third aspect of this invention provides the application of the composite metal oxide described in the first aspect or the composite metal oxide prepared by the preparation method described in the second aspect in dehydrogenation reactions. Using the composite metal oxide provided by this invention as a catalyst in dehydrogenation reactions can significantly improve the catalytic activity, stability, and selectivity of the target product. This invention has a wide range of applications for the dehydrogenation reactions, preferably in the dehydrogenation reactions of lower alcohols or lower alkanes, and more preferably in the dehydrogenation reaction of 1,4-butanediol. The lower alcohols or lower alkanes described in this invention each have an independent number of carbon atoms of 2-5.

[0083] The fourth aspect of the present invention provides a method for the dehydrogenation reaction of 1,4-butanediol, the method comprising: contacting 1,4-butanediol with a dehydrogenation catalyst in the presence of hydrogen and under dehydrogenation reaction conditions, wherein the dehydrogenation catalyst comprises the composite metal oxide described in the first aspect or the composite metal oxide prepared by the preparation method described in the second aspect.

[0084] The composite metal oxide provided by this invention is not only applicable to the conventional 1,4-butanediol dehydrogenation reaction temperature in the prior art, but the inventors have also discovered that it is equally applicable to lower dehydrogenation reaction temperatures than the prior art. This not only reduces the reaction temperature but also significantly improves catalytic activity, stability, and target product selectivity. For example, at a reaction temperature of 190°C, after a long reaction period of 600 hours, the conversion rate can still reach 99.7%, the selectivity can reach 98.7%, and the yield can reach 98.4%.

[0085] According to the present invention, preferably, the conditions for the dehydrogenation reaction include: a reaction temperature of 150-300°C and a volume hourly space velocity of 0.5-3 h⁻¹. -1 The molar ratio of hydrogen alcohol is (3-10):1; more preferably, the reaction temperature is 180-270℃, more preferably 180-220℃, and the volume hourly space velocity is 1-2.5h. -1The hydrogen-to-alcohol molar ratio is (4-7):1. The composite metal oxide provided by this invention can be applied to a wider temperature range. In the prior art, the dehydrogenation reaction temperature of 1,4-butanediol is generally 220-280℃, while the composite metal oxide of this invention can also be applied to lower reaction temperatures.

[0086] According to one specific embodiment of the present invention, before the composite metal oxide is used in the dehydrogenation reaction, a reduction treatment step is further included, which can be carried out according to conventional techniques in the art. Preferably, the reduction conditions include: carrying out the reaction in a hydrogen-containing atmosphere (provided by hydrogen and optionally an inert atmosphere, wherein the volume content of hydrogen is preferably 5% or more), at a temperature of 230-290°C, for a time of 4-9 hours; preferably, the hydrogen flow rate is 180-220 ml / min relative to 100 ml of catalyst. The inert atmosphere includes, but is not limited to, nitrogen, helium, argon, and neon.

[0087] The preparation process and product performance of the method of the present invention will be further illustrated below with reference to the embodiments and comparative examples, but the following embodiments do not constitute a limitation on the method of the present invention.

[0088] In the following examples and comparative examples of composite metal oxides:

[0089] X-ray diffraction (XRD) tests were performed using a Rigaku D / max2500 X-ray diffractometer, Cu target, Kα radiation source, 80 mA current, and a wide-angle scanning range of 5°–70°.

[0090] The molar ratio of copper, zirconium, and metal M was determined by X-ray fluorescence spectroscopy (XRF).

[0091] The dispersion of copper was determined using the N2O / H2-TPR method.

[0092] The specific surface area was obtained by nitrogen isothermal adsorption-desorption method.

[0093] The specific conditions for each test method are as described above.

[0094] In the following examples and comparative examples, F127 was purchased from Maclean's Reagents, specifically a product with an average Mn of 15000. P123 was purchased from Maclean's Reagents, specifically a product with an average Mn of 5800.

[0095] When the composite metal oxides described above are used in dehydrogenation reactions, the composite metal oxides and the dehydrogenation catalysts in the following examples and comparative examples have the same meaning.

[0096] Example 1

[0097] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0098] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is aged at 17℃ for 15 h. Then it is filtered and washed to obtain the precipitate.

[0099] (3) The precipitate was dried at 80℃ for 15 hours, calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD pattern is shown in [Table 1]. Figure 1 .from Figure 1 It can be seen that the XRD pattern of the dehydrogenation catalyst prepared in this embodiment has diffraction peaks at 2θ positions of 29.3°, 36.2°, 56.6°, and 68.0°.

[0100] Figure 2 The image shows a SEM image of the dehydrogenation catalyst prepared in this embodiment. It can be seen from the image that the product has a microstructure size at the nanoscale, a large specific surface area, and good component dispersion.

[0101] Example 2

[0102] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.33g of solid P123 and heat to 55℃ to dissolve completely.

[0103] (2) The mixed solution obtained in step (1) is mixed with a 1.5 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature is controlled at 50℃ and the pH is 8. The feeding time of the co-precipitation reaction is controlled at 30 min. After the feeding is completed, the mixture is stirred at 50℃ for 20 min. Then, it is allowed to stand at 20℃ for 15 h for aging. Then, it is filtered and washed to obtain the precipitate.

[0104] (3) The precipitate was dried at 80℃ for 16 hours, calcined at 150℃ for 4 hours, and then calcined at 390℃ for 4 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0105] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.2°, 36.5°, 56.4°, and 67.7°.

[0106] Example 3

[0107] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 25.60g Mn(NO3)2·4H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 0.89g of solid F127 and heat to 50℃ to dissolve completely.

[0108] (2) The mixed solution obtained in step (1) was mixed with a 1.0 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature was controlled at 70℃ and the pH was 8.5. The feeding time of the co-precipitation reaction was controlled at 20 min. After the feeding was completed, the mixture was stirred at 70℃ for 30 min. Then it was allowed to stand at 17℃ for 14 h for aging. After filtration and washing, the precipitate was obtained.

[0109] (3) The precipitate was dried at 75℃ for 12 hours, calcined at 220℃ for 1 hour, and then calcined at 430℃ for 2 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0110] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.5°, 36.0°, 56.8°, and 68.2°.

[0111] Example 4

[0112] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 38.26g Al(NO3)3·9H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0113] (2) The mixed solution obtained in step (1) was mixed with a 1.2 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature was controlled at 60℃ and the pH was 8. The feeding time of the co-precipitation reaction was controlled at 20 min. After the feeding was completed, the mixture was stirred at 60℃ for another 20 min. Then it was allowed to stand at 17℃ for 15 h for aging. After filtration and washing, the precipitate was obtained.

[0114] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0115] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.2°, 36.3°, 56.7°, and 68.1°.

[0116] Example 5

[0117] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 24.27g Zn(NO3)2·6H2O, and 72.32g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 0.8g of solid F127 and heat to 50℃ to dissolve completely.

[0118] (2) The mixed solution obtained in step (1) was mixed with a 1.2 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature was controlled at 60℃ and the pH was 8. The feeding time of the co-precipitation reaction was controlled at 20 min. After the feeding was completed, the mixture was stirred at 60℃ for another 20 min. Then it was allowed to stand at 17℃ for 15 h for aging. After filtration and washing, the precipitate was obtained.

[0119] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0120] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.1°, 36.0°, 56.9°, and 68.1°.

[0121] Example 6

[0122] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 36.40g Zn(NO3)2·6H2O, and 59.16g ZrOCl2·8H2O in 80ml of deionized water, stir at 400r / min, and maintain a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0123] (2) The mixed solution obtained in step (1) was mixed with a 1.2 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature was controlled at 55℃ and the pH was 8.5. The feeding time of the co-precipitation reaction was controlled at 25 min. After the feeding was completed, the mixture was stirred at 55℃ for another 25 min. Then, it was allowed to stand at 20℃ for 14 h for aging. After filtration and washing, the precipitate was obtained.

[0124] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 160℃ for 3 hours, and then calcined at 410℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0125] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.2°, 36.5°, 56.4°, and 67.7°.

[0126] Example 7

[0127] (1) In a beaker, dissolve 76.40g CuSO4·5H2O, 16.47g ZnSO4, and 87.58g Zr(NO3)4·5H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0128] (2) The mixed solution obtained in step (1) is mixed with 1.4 mol / L sodium carbonate precipitant solution for coprecipitation. The temperature is controlled at 60℃ and the pH is 8.5. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is allowed to stand at 17℃ for 15 h for aging. Then it is filtered and washed to obtain the precipitate.

[0129] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0130] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.3°, 36.2°, 56.6°, and 68.0°.

[0131] Example 8

[0132] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 0.36g of solid F127 and heat to 50℃ to dissolve completely.

[0133] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium hydroxide solution as a precipitant and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is allowed to stand at 17℃ for 15 h for aging. Then it is filtered and washed to obtain the precipitate.

[0134] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0135] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.3°, 36.2°, 56.6°, and 68.0°.

[0136] Example 9

[0137] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 15.17g Zn(NO3)2·6H2O, and 42.73g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0138] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is allowed to stand at 20℃ for 15 h for aging. Then it is filtered and washed to obtain the precipitate.

[0139] (3) The precipitate was dried at 80℃ for 15 hours, calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. The XRD pattern of the dehydrogenation catalyst in this embodiment is shown in Table 1. Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.2°, 36.5°, 56.4°, and 67.7°.

[0140] Example 10

[0141] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 51.58g Zn(NO3)2·6H2O, and 88.75g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.33g of solid P123 and heat to 50℃ to dissolve completely.

[0142] (2) The mixed solution obtained in step (1) is mixed with a 1.5 mol / L sodium carbonate precipitant solution for co-precipitation. The temperature is controlled at 50℃ and the pH is 8. The feeding time of the co-precipitation reaction is controlled at 30 min. After the feeding is completed, the mixture is stirred at 50℃ for 20 min. Then, it is allowed to stand at 20℃ for 15 h for aging. Then, it is filtered and washed to obtain the precipitate.

[0143] (3) The precipitate was dried at 80℃ for 15 hours, then calcined at 150℃ for 4 hours, and then calcined at 390℃ for 4 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1.

[0144] The XRD pattern of the dehydrogenation catalyst described in this embodiment is consistent with... Figure 1 Similarly, diffraction peaks are observed at 2θ values ​​of 29.2°, 36.5°, 56.4°, and 67.7°.

[0145] Comparative Example 1

[0146] (1) Dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water in a beaker, stir at 400r / min, and keep at a constant temperature of 30℃. After complete dissolution, add water to 200ml.

[0147] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is aged at 17℃ for 15 h. Then it is filtered and washed to obtain the precipitate.

[0148] (3) The precipitate was dried at 80℃ for 15 hours, calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD pattern is shown in [Table 1]. Figure 3 .from Figure 3 It can be concluded that Zr3O is not present in the catalyst. 1-x .

[0149] Comparative Example 2

[0150] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of sodium dodecyl sulfate solid and heat to 50℃ until fully dissolved.

[0151] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is aged at 17℃ for 15 h. Then it is filtered and washed to obtain the precipitate.

[0152] (3) The precipitate was dried at 80℃ for 15 h, calcined at 180℃ for 2 h, and then calcined at 400℃ for 3 h to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD results showed that Zr3O was not present in the catalyst. 1-x .

[0153] Comparative Example 3

[0154] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 60.68g Zn(NO3)2·6H2O, and 19.72g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0155] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is aged at 17℃ for 15 h. Then it is filtered and washed to obtain the precipitate.

[0156] (3) The precipitate was dried at 80℃ for 15 hours, calcined at 180℃ for 2 hours, and then calcined at 400℃ for 3 hours to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD pattern is shown in [Table 1]. Figure 4 .from Figure 4 It can be seen that the zirconium oxide in the catalyst does not contain Zr3O. 1-x Crystal phase.

[0157] Comparative Example 4

[0158] (1) In a beaker, dissolve 73.91g Cu(NO3)2·3H2O, 30.34g Zn(NO3)2·6H2O, and 65.74g ZrOCl2·8H2O in 80ml of deionized water, stirring at 400r / min and maintaining a constant temperature of 30℃. After complete dissolution, add water to a final volume of 200ml. Add 1.5g of solid F127 and heat to 50℃ to dissolve completely.

[0159] (2) The mixed solution obtained in step (1) is mixed with 1.2 mol / L sodium carbonate precipitant solution and then coprecipitated. The temperature is controlled at 60℃ and the pH is 8.0. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is stirred at 60℃ for 20 min. Then it is allowed to stand at 17℃ for 15 h for aging. Then it is filtered and washed to obtain the precipitate.

[0160] (3) The precipitate was dried at 80℃ for 15 h and then calcined at 400℃ for 5 h to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD pattern is shown in Table 1. Figure 5 .from Figure 5 It can be concluded that Zr3O is not present in the catalyst. 1-x .

[0161] Comparative Example 5

[0162] (1) Dissolve 73.91g Cu(NO3)2·3H2O, 72.82g Zn(NO3)2·6H2O, and 19.72g Zr(NO3)4·5H2O in 80ml of deionized water in a beaker, stir at 400r / min, and keep at a constant temperature of 30℃. After complete dissolution, add water to make the concentration of copper nitrate 0.81mol / L.

[0163] (2) The mixed solution obtained in step (1) is mixed with 1 mol / L sodium carbonate solution as a precipitant and then coprecipitated. During the reaction, the mixture is stirred and the temperature is controlled at 70℃ and the pH is 7-7.5. The feeding time of the coprecipitation reaction is controlled at 20 min. After the feeding is completed, the mixture is allowed to stand at 70℃ for 30 min, and then allowed to stand at room temperature for 20 h. The reaction mixture after standing is then filtered to obtain the precipitate.

[0164] (3) The precipitate was dried at 80℃ for 15 h and then calcined at 350℃ for 4 h to obtain the dehydrogenation catalyst. The composition and properties of the dehydrogenation catalyst are shown in Table 1. XRD results showed that Zr3O was not present in the catalyst. 1-x .

[0165] Table 1. Composition and properties of various dehydrogenation catalysts

[0166]

[0167] Application examples

[0168] This application example illustrates the dehydrogenation performance of the composite metal oxide provided by this invention in a dehydrogenation reaction. The catalysts of the above examples and comparative examples were tested under the same conditions. Specifically, the catalysts were first reduced under the following conditions: catalyst loading of 100 ml (sieved through a 20-40 mesh), hydrogen flow rate of 200 ml / min, nitrogen flow rate of 1800 ml / min, and reduction at 270°C for 6 h. Then, in the presence of hydrogen and under dehydrogenation reaction conditions, the catalysts of the examples and comparative examples were reacted with 1,4-butanediol, respectively. The dehydrogenation reaction conditions included: reaction temperature of 190°C and volume hourly space velocity of 2.0 h⁻¹. -1 The molar ratio of hydrogen alcohol was 5:1. The test results are shown in Table 2.

[0169] In Table 2, the conversion rate refers to the mass conversion rate of 1,4-butanediol. The selectivity is the selectivity of γ-butyrolactone, calculated as the ratio of the mass of γ-butyrolactone to the total mass of the product. The yield is the yield of γ-butyrolactone, calculated as the product of the conversion rate of 1,4-butanediol and the selectivity of γ-butyrolactone.

[0170] Table 2 Evaluation results of each dehydrogenation catalyst

[0171]

[0172] As can be seen from the results of the embodiments and comparative examples of the present invention, the composite metal oxide provided by the present invention exhibits high catalytic activity, selectivity and stability when used in the dehydrogenation reaction of 1,4-butanediol, even at a temperature of 190°C.

[0173] The specific embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite metal oxide characterized in that, The composite metal oxide comprises a copper element, a zirconium element, and a metal M element selected from at least one of a zinc element, an aluminum element, a manganese element, a titanium element, and a cerium element, wherein the oxide of zirconium comprises ZrO2 and Zr3O 1-x , and x is greater than 0 and less than 1.

2. The composite metal oxide according to claim 1, wherein ZrO2and Zr3O 1-x in a molar ratio of 4-7:1, preferably 5-6:

1.

3. The composite metal oxide according to claim 1, wherein The composite metal oxide has a diffraction peak at 29.3±0.3°, preferably at 29.3±0.3°, 36.2±0.3°, 56.6±0.3°, 68.0±0.3°, as measured by X-ray diffraction.

4. The composite metal oxide according to claim 1, wherein The molar ratio of copper element, zirconium element and metal M element is 3:(1.1-3):(0.5-2), preferably 3:(1.3-2.7):(0.5-1.7), more preferably 3:(1.8-2.3):(0.8-1.2).

5. The composite metal oxide according to any one of claims 1 to 4, wherein The dispersion degree of copper is 50%-80%, preferably 55%-75%.

6. The composite metal oxide according to any one of claims 1-5, wherein, The specific surface area of the composite metal oxide is 70 to 100 m 2 / g, preferably 75 to 100 m 2 / g.

7. A method for preparing a composite metal oxide, comprising the following steps: (1) co-precipitation reaction of a copper source, a zirconium source, a M source and a precipitant in the presence of a non-ionic surfactant, to obtain a reaction product; M is selected from at least one of zinc, aluminum, manganese, titanium and cerium; (2) pre-calcination and calcination of the reaction product of step (1), the temperature of the pre-calcination being 150-250℃; The amount of the copper source, the zirconium source and the M source is such that the molar ratio of copper element, zirconium element and metal M element in the prepared composite metal oxide is 3:(1.1-3):(0.5-2), preferably 3:(1.3-2.7):(0.5-1.7), more preferably 3:(1.8-2.3):(0.8-1.2).

8. The method of claim 7, wherein, In step (1), the non-ionic surfactant is at least one of polyether non-ionic surfactants, preferably F127 and / or P123; Preferably, the amount of the non-ionic surfactant added is 0.5wt%-2.2wt% of the amount of the copper source added, further preferably 1wt%-2wt%; Preferably, in step (1), the copper source, the zirconium source and the M source are each independently selected from soluble salts of metals.

9. The method of preparation according to claim 7 or 8, wherein, The precipitant in step (1) is selected from at least one of NaOH, Na2CO3, NaHCO3, NH4HCO3 and ammonia; Preferably, in step (1), the co-precipitation is parallel flow precipitation; Preferably, in step (1), the conditions of the co-precipitation reaction include: reaction temperature of 40-80℃, reaction time of 10-60min, and pH value of the reaction system of 7.5-10.

10. The method of any one of claims 7-9, wherein, The method further comprises aging the reaction product obtained in step (1), and then performing the step (2); Preferably, the conditions of the aging include: temperature of 10-80℃, and aging time of 10-20h.

11. The method of manufacturing according to any one of claims 7-10, wherein, In step (2), the temperature of the pre-calcination is 150-220℃; And / or, the time of the pre-calcination is 1-4h; And / or, the conditions of the calcination include: temperature of 300-500℃, and time of 1-8h, preferably temperature of 300-450℃, and time of 2-4h.

12. Use of the composite metal oxide according to any one of claims 1 to 6 or of the composite metal oxide produced according to the production process according to any one of claims 7 to 11 in a dehydrogenation reaction, preferably in a dehydrogenation reaction of a lower alkanol or of a lower alkane, more preferably in a dehydrogenation reaction of 1,4-butanediol.

13. A method for dehydrogenation of 1,4-butanediol, the method comprising: contacting 1,4-butanediol with a dehydrogenation catalyst in the presence of hydrogen under dehydrogenation reaction conditions, the dehydrogenation catalyst comprising the composite metal oxide according to any one of claims 1 to 6 or of the composite metal oxide produced according to the production process according to any one of claims 7 to 11 ; Preferably, the conditions of the dehydrogenation reaction comprise a reaction temperature of 150-300°C, preferably 180-270°C, further preferably 180-220°C, a volume hourly space velocity of 0.5-3 h -1 , a hydrogen alcohol molar ratio of (3-10): 1.

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