Zinc oxide-zirconium oxide catalyst and preparation method thereof, composite catalyst and application thereof, and method for preparing hydrocarbons through carbon dioxide hydrogenation

Abstract

The invention relates to the field of catalyst preparation, and discloses a zinc oxide-zirconium oxide catalyst and a preparation method thereof, a composite catalyst and application thereof, and a method for preparing hydrocarbons through carbon dioxide hydrogenation. The invention relates to a preparation method of a zinc oxide-zirconium oxide catalyst, which comprises the following steps: (1) placing zinc oxide at the upstream of zirconium oxide along the introduction direction of carrier gas under the action of the carrier gas, and then carrying out heat treatment; according to the zinc oxide-zirconium oxide catalyst prepared by the method disclosed by the invention, the obtained composite catalyst has excellent catalytic performance. The composite catalyst is applied to a reaction for preparing hydrocarbon compounds through carbon dioxide hydrogenation, and the selectivity of target hydrocarbon products is high.

Description

Technical Field

[0001] The invention relates to the field of catalyst preparation, and in particular to a zinc oxide-zirconium oxide catalyst and a preparation method thereof, a composite catalyst and an application thereof, and a method for preparing hydrocarbons by hydrogenating carbon dioxide. Background Art

[0002] Carbon dioxide is one of the main gases causing the greenhouse effect. Industrial production processes emit a large amount of carbon dioxide. With global warming, the control of carbon emissions has become particularly important. Using carbon dioxide as a carbon source for reactions and preparing chemicals using carbon dioxide is an important way to utilize carbon dioxide. Since carbon dioxide molecules have high symmetry, high bond energy, and are difficult to activate, carbon dioxide is usually converted into methanol, formic acid, low-carbon olefins, and C 5+ Chemicals such as hydrocarbons.

[0003] There are currently two routes for producing hydrocarbons from carbon dioxide. One is to use iron-based, cobalt-based and other catalysts of Fischer-Tropsch synthesis to convert carbon dioxide into carbon monoxide through reverse water gas shift, and then produce hydrocarbons through Fischer-Tropsch synthesis. However, the product distribution of this route is limited by the distribution law of Fischer-Tropsch synthesis products (Anderson-Schultz-Flory, ASF). The other is to hydrogenate carbon dioxide through oxygen-containing compounds such as methanol, and then produce hydrocarbons through methanol to hydrocarbons (MTH) reaction on acidic molecular sieves. This route can obtain higher hydrocarbon selectivity. However, when the second route is used to produce hydrocarbons in the prior art, low-carbon olefins and C 5+ The yield of target hydrocarbons such as hydrocarbons is low. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art, and to provide a zinc oxide-zirconia catalyst and a preparation method, a composite catalyst and an application thereof, and a method for hydrogenating carbon dioxide to produce hydrocarbons. The zinc oxide-zirconia catalyst prepared by the method of the present invention has excellent catalytic performance. The composite catalyst is applied to the reaction of hydrogenating carbon dioxide to produce hydrocarbon compounds, and the target hydrocarbon product has high selectivity.

[0005] In order to achieve the above object, the present invention provides a method for preparing a zinc oxide-zirconium oxide catalyst, which comprises: placing zinc oxide upstream of zirconium oxide along the direction of carrier gas introduction under the action of carrier gas, and then performing heat treatment.

[0006] Preferably, the heat treatment conditions include: temperature of 500-1000° C., preferably 600-800° C.; time of 2-10 h, preferably 4-6 h.

[0007] Preferably, the volume space velocity of the carrier gas relative to zinc oxide is 2000-8000h-1 , preferably 3000-7000h -1 .

[0008] Preferably, the carrier is a reducing gas, preferably at least one selected from hydrogen, carbon monoxide and ammonia.

[0009] The second aspect of the present invention provides a zinc oxide-zirconium oxide catalyst prepared by the method described in the first aspect.

[0010] The third aspect of the present invention provides a composite catalyst, the composite catalyst comprising: the zinc oxide-zirconium oxide catalyst and the molecular sieve catalyst described in the second aspect;

[0011] Wherein, based on the total weight of the composite catalyst, the content of the molecular sieve catalyst is 35-95wt%; the content of the zinc oxide-zirconium oxide catalyst is 5-65wt%.

[0012] The fourth aspect of the present invention provides an application of the composite catalyst described in the third aspect in the preparation of hydrocarbon compounds by hydrogenation of carbon dioxide.

[0013] A fifth aspect of the present invention provides a method for preparing hydrocarbon compounds by hydrogenating carbon dioxide, the method comprising: contacting carbon dioxide, hydrogen and optionally a diluent gas under the action of a catalyst to obtain a target hydrocarbon product;

[0014] Wherein, the catalyst is the composite catalyst described in the third aspect.

[0015] Through the above technical solution, the beneficial effects of the present invention include:

[0016] The zinc oxide-zirconium oxide catalyst prepared by the method of the present invention has excellent catalytic performance. The composite catalyst is used in the reaction of preparing hydrocarbon compounds by hydrogenation of carbon dioxide, and the target hydrocarbon product has high selectivity. The selectivity of C2-C4 olefins in the hydrocarbon product can reach up to 84.9%, and the selectivity of C 5+ The selectivity of hydrocarbons can reach up to 68.2%, while the selectivity of by-product CH4 is lower, reaching a minimum of 4.3%. DETAILED DESCRIPTION

[0017] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0018] On one hand, the present invention provides a method for preparing a zinc oxide-zirconium oxide catalyst, which comprises: placing zinc oxide upstream of zirconium oxide along the direction of carrier gas introduction under the action of carrier gas, and then performing heat treatment.

[0019] According to a preferred embodiment of the present invention, the heat treatment causes zinc oxide to be deposited on zirconium oxide.

[0020] The inventors have found that heat treatment under specific conditions is more conducive to obtaining the catalyst with excellent catalytic performance described in the present invention.

[0021] According to the present invention, preferably, the heat treatment conditions include: a temperature of 500-1000° C., preferably 600-800° C.; and a time of 2-10 h, preferably 4-6 h.

[0022] According to the present invention, preferably, the volume space velocity of the carrier gas relative to zinc oxide is 2000-8000h -1 , preferably 3000-7000h -1 . The use of this preferred embodiment is further conducive to obtaining the catalyst with excellent catalytic performance described in the present invention. When the volume space velocity of the carrier gas relative to zinc oxide is lower than this range, it will lead to incomplete reduction of zinc oxide, uneven reaction, and poor deposition effect; when the volume space velocity of the carrier gas relative to zinc oxide is higher than this range, the vaporized reduction product and zirconium oxide will not have time to react, resulting in the inability to effectively deposit on zirconium oxide.

[0023] Preferably, the carrier gas is a reducing gas, and in order to improve the deposition effect, it is preferably selected from at least one of hydrogen, carbon monoxide and ammonia.

[0024] It is understandable that in the heat treatment process of the present invention, under the action of the carrier gas (reducing gas), the zinc oxide will first be reduced to obtain a reduction product, and then under the heat treatment conditions, the reduction product will be further vaporized and deposited on the zirconium oxide.

[0025] The zinc oxide of the present invention may include zinc oxide, and may also include zinc oxides of other valence states. Since the valence state does not affect the subsequent reaction effect of hydrogenating carbon dioxide to prepare hydrocarbon compounds, it will not be described in detail.

[0026] According to the present invention, preferably, the amount of zinc oxide and zirconium oxide used is such that the mass ratio of zinc oxide to zirconium oxide in the prepared zinc oxide-zirconium oxide catalyst is 0.004-0.1, preferably 0.01-0.08. By adopting this preferred embodiment, the composite catalyst obtained subsequently has excellent catalytic performance.

[0027] In the present invention, in order to obtain the zinc oxide-zirconia catalyst having the above composition, the zinc oxide is generally controlled to be excessive so that the active sites on the surface of the zirconium oxide can fully react with the reduction product of the zinc oxide. Preferably, the mass ratio of the zinc oxide to the zirconium oxide is 0.5-4.

[0028] The present invention has no particular limitation on the sources of the zinc oxide and zirconium oxide, which can be obtained from commercial sources or prepared by conventional preparation methods in the art.

[0029] According to the present invention, preferably, the zinc oxide and the zirconium oxide are placed at intervals. This preferred embodiment is conducive to the effective reduction of zinc oxide and its reaction with zirconium oxide, and the unreacted zinc oxide can also be recovered.

[0030] The present invention has no particular limitation on the method for achieving the spacing, and conventional technical means in the art may be used. Preferably, an inert filler is placed between the zinc oxide and the zirconium oxide.

[0031] The present invention has a wide selection range for the inert filler, which can be a conventional choice in the art. Preferably, the inert filler is selected from at least one of quartz sand, α-alumina ceramic balls and quartz wool.

[0032] According to a particularly preferred embodiment of the present invention, a method for preparing a zinc oxide-zirconium oxide catalyst comprises: placing zinc oxide upstream of zirconium oxide along the direction of carrier gas introduction, and then performing heat treatment;

[0033] The heat treatment conditions include: temperature of 600-800°C and time of 4-6h;

[0034] The volume space velocity of the carrier gas relative to zinc oxide is 3000-7000h -1 ;

[0035] The carrier gas is a reducing gas;

[0036] The amounts of zinc oxide and zirconium oxide used are such that the mass ratio of zinc oxide to zirconium oxide in the prepared zinc oxide-zirconium oxide catalyst is 0.01-0.08.

[0037] The zinc oxide-zirconium oxide catalyst prepared by the above preferred embodiment further enables the obtained composite catalyst to have excellent catalytic performance.

[0038] The second aspect of the present invention provides a zinc oxide-zirconium oxide catalyst prepared by the method described in the first aspect.

[0039] According to the present invention, preferably, in the zinc oxide-zirconium oxide catalyst, the mass ratio of zinc oxide to zirconium oxide is 0.004-0.1, preferably 0.01-0.08.

[0040] The third aspect of the present invention provides a composite catalyst, the composite catalyst comprising: the zinc oxide-zirconium oxide catalyst and the molecular sieve catalyst described in the second aspect;

[0041] Wherein, based on the total weight of the composite catalyst, the content of the molecular sieve catalyst is 35-95wt%; the content of the zinc oxide-zirconium oxide catalyst is 5-65wt%.

[0042] According to the present invention, preferably, based on the total weight of the composite catalyst, the content of the molecular sieve catalyst is 45-70wt%; the content of the zinc oxide-zirconium oxide catalyst is 30-55wt%.

[0043] The present invention has no particular limitation on the type of the molecular sieve, which can be a conventional choice in the art. Preferably, the molecular sieve is at least one of CHA structure, MFI structure, MFS structure and MTF structure molecular sieve, preferably at least one of SAPO-34, ZSM-5, ZSM-57 and MCM-35 molecular sieve. Using this preferred embodiment, the prepared composite catalyst is applied to the reaction of preparing hydrocarbon compounds by hydrogenation of carbon dioxide, which is beneficial to improve the selectivity of the target hydrocarbon product.

[0044] According to the present invention, preferably, the silicon-aluminum atomic ratio of the molecular sieve is 0.02-400, preferably 0.2-400.

[0045] Preferably, the silicon to aluminum atomic ratio of the SAPO-34 molecular sieve is 0.2-0.6.

[0046] Preferably, the silicon to aluminum atomic ratio of the ZSM-5 molecular sieve is 20-360.

[0047] Preferably, the silicon to aluminum atomic ratio of the ZSM-57 molecular sieve is 15-30.

[0048] Preferably, the silicon to aluminum atomic ratio of the MCM-35 molecular sieve is 20-150.

[0049] Preferably, the molecular sieve is a hydrogen-type molecular sieve.

[0050] The present invention has no particular limitation on the method for obtaining the hydrogen molecular sieve, and the method can be carried out according to conventional methods in the art. The present invention preferably uses an ammonia exchange method to obtain the hydrogen molecular sieve.

[0051] The ammonia exchange method of the present invention can be carried out by referring to the conventional ammonia exchange method in the art, and the present invention will not be described in detail here.

[0052] The present invention has no particular limitation on the preparation method of the composite catalyst, and the preparation method can be carried out according to conventional methods in the art. The present invention preferably adopts a physical mixing method.

[0053] According to a specific embodiment of the present invention, the zinc oxide-zirconium oxide catalyst and the molecular sieve catalyst are ground to obtain a composite catalyst.

[0054] The particle size of the composite catalyst is a conventional choice in the art. Preferably, the particle size of the composite catalyst is 20-80 meshes.

[0055] The present invention has no particular limitation on the method for obtaining the catalyst with the particle size, and the method may refer to conventional technical means in the art.

[0056] The fourth aspect of the present invention provides an application of the composite catalyst described in the third aspect in the preparation of hydrocarbon compounds by hydrogenation of carbon dioxide.

[0057] A fifth aspect of the present invention provides a method for preparing hydrocarbon compounds by hydrogenating carbon dioxide, the method comprising: contacting carbon dioxide, hydrogen and optionally a diluent gas under the action of a catalyst to obtain a target hydrocarbon product;

[0058] Wherein, the catalyst is the composite catalyst described in the third aspect.

[0059] According to the present invention, preferably, the molar ratio of hydrogen to carbon dioxide is 3-15:1, preferably 3-10:1.

[0060] In the present invention, unless otherwise specified, the term "optionally" means containing or not containing, adding or not adding, adopting or not adopting. Specifically, the method of the present invention may or may not add a diluent.

[0061] The diluent gas of the present invention can be a conventional choice in the art. Preferably, the diluent gas is selected from at least one of nitrogen, helium, argon and carbon monoxide.

[0062] According to the present invention, preferably, the molar ratio of the diluent gas to carbon dioxide is 0.1-0.2:1.

[0063] According to the present invention, preferably, the reaction conditions are: temperature of 250-450°C, preferably 320-450°C; pressure of 0.3-20MPa, preferably 2-15MPa; volume space velocity of carbon dioxide of 0.01-10h -1 , preferably 0.05-8h -1 .

[0064] Preferably, the target hydrocarbon product is C2-C4 olefins and / or C 5+ Hydrocarbons.

[0065] The reaction of the present invention can be carried out in various conventional reactors in the art, for example, in a fixed bed reactor, in a fluidized bed reactor, or in a moving bed reactor.

[0066] Preferably, the composite catalyst is reduced before use.

[0067] The present invention has no particular limitation on the reduction method, and the reduction may be carried out according to conventional methods in the art.

[0068] According to a preferred embodiment of the present invention, under the action of reducing gas, the composite catalyst is reduced at 380-450° C. for 2-6 hours.

[0069] Preferably, the reducing gas is hydrogen.

[0070] The present invention will be described in detail below through examples.

[0071] In the following examples, the conversion rate of carbon dioxide was calculated using the internal standard method, and the selectivity of the product was calculated using the normalization method, and the formula is as follows:

[0072] Carbon dioxide conversion rate = [(carbon dioxide moles in the feed gas) - (carbon dioxide moles in the product)] / (carbon dioxide moles in the feed gas) × 100%;

[0073] Selectivity of hydrocarbon products = molar number of carbon in hydrocarbon products / total molar number of organic carbon in hydrocarbon products × 100%;

[0074] CO selectivity = molar number of CO carbon in the product / [molar number of carbon dioxide carbon in the feed gas - molar number of carbon dioxide carbon in the product] × 100%;

[0075] The specific sources of the molecular sieve catalysts used in the following examples are shown in Table 1.

[0076] Table 1

[0077]

[0078] Example 1

[0079] Preparation of zinc oxide-zirconia catalyst

[0080] Preparation of ZrO2 carrier: 18.6g zirconium oxynitrate was dissolved in 200mL water, concentrated ammonia (25-28wt%) was added at room temperature to pH≈8.0, and sodium hydroxide was added to obtain a colloidal precipitate to adjust the pH to 14. The mixture was aged for 1 hour, filtered, washed, and dried, and then calcined at 500°C for 3h. The ZrO2 was naturally cooled to obtain ZrO2, which was sieved into 40-60 mesh particles.

[0081] 1.0g ZrO2 was placed in the lower layer of the quartz tube, and 1.0g zinc oxide was placed in the upper layer. The tube was separated by quartz wool, and hydrogen flowed from the upper layer to the lower layer. The tube was treated at 600℃ for 6h in a hydrogen atmosphere, and the volumetric space velocity of hydrogen was 6000h -1 The zinc oxide-zirconia catalyst obtained by cooling down the lower layer was taken out and recorded as Zn@ZrO2. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.07:1.

[0082] Preparation of composite catalyst

[0083] The 0.5 g Zn@ZrO2 catalyst prepared above and 1.0 g HSAPO-34 were fully ground and mixed to obtain a composite catalyst, which was recorded as C-1. The composite catalyst was tableted and granulated to prepare 40-60 mesh particles for subsequent reactions.

[0084] Example 2

[0085] Preparation of zinc oxide-zirconia catalyst

[0086] The lower layer of the quartz tube was filled with 1.0 g ZrO2 obtained in Example 1, and the upper layer was filled with 1.0 g zinc oxide. The middle was separated by quartz wool, and hydrogen flowed from the upper layer to the lower layer. The treatment was carried out at 700 ° C for 4 h in a hydrogen atmosphere, and the volume space velocity of hydrogen was 6000 h -1 The zinc oxide-zirconia catalyst obtained by cooling down the bottom layer was taken out and recorded as Zn@ZrO2. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.08:1.

[0087] Preparation of composite catalyst

[0088] Preparation of HMCM-35 molecular sieve: In a hydrothermal synthesis reactor, add Na-MCM-35 molecular sieve powder to a pre-prepared 1 mol / L NH4Cl aqueous solution, with a solid-liquid mass ratio of 1:10, and perform exchange reaction at 80°C for 2 hours under stirring, vacuum filter and wash with water. After performing the above exchange, filtration and washing operations three times, dry at 120°C for 4 hours. Then, after calcining at 550°C for 4 hours, H-MCM-35 is obtained.

[0089] The above-prepared 0.5 g Zn@ZrO2 and 0.5 g HMCM-35 were fully ground and mixed to obtain a composite catalyst, which was recorded as C-2. The composite catalyst was tableted and granulated to prepare 40-60 mesh particles for subsequent reactions.

[0090] Example 3

[0091] Preparation of zinc oxide-zirconia catalyst

[0092] Preparation of ZrO2 carrier: according to the method of Example 1.

[0093] 1.0g ZrO2 was placed in the lower layer of the quartz tube, and 1.0g zinc oxide was placed in the upper layer. The tube was separated by quartz wool, and hydrogen flowed from the upper layer to the lower layer. The tube was treated at 800℃ for 6h in a hydrogen atmosphere, and the volumetric space velocity of hydrogen was 4000h -1 The zinc oxide-zirconia catalyst obtained by cooling down the bottom layer was taken out and recorded as Zn@ZrO2. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.08:1.

[0094] Preparation of composite catalyst

[0095] Preparation of H-ZSM-57 molecular sieve: In a hydrothermal synthesis reactor, add Na-ZSM-57 molecular sieve powder to a pre-prepared 1 mol / L NH4Cl aqueous solution, with a solid-liquid mass ratio of 1:10, and perform exchange reaction at 80°C for 2 hours under stirring, vacuum filter and wash with water. After performing the above exchange, filtration and washing operations three times, dry at 120°C for 4 hours. Then, after calcination at 550°C for 4 hours, H-ZSM-57 is obtained.

[0096] The above-prepared 0.6g Zn@ZrO2 and 0.8g HZSM-57 were fully ground and mixed to obtain a composite catalyst, which was recorded as C-3. The composite catalyst was tableted and granulated to prepare 40-60 mesh particles for subsequent reactions.

[0097] Example 4

[0098] Preparation of zinc oxide-zirconia catalyst

[0099] Preparation of ZrO2 carrier: according to the method of Example 1.

[0100] 1.0g ZrO2 is placed in the lower layer of the quartz tube, and 1.0g zinc oxide is placed in the upper layer. The middle is separated by quartz wool, and hydrogen flows from the upper layer to the lower layer. The treatment is carried out at 600℃ for 5h in a hydrogen atmosphere, and the volume space velocity of hydrogen is 6000h -1 The zinc oxide-zirconia catalyst obtained by cooling down the lower layer is taken out and recorded as Zn@ZrO2. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide is 0.05:1.

[0101] Preparation of composite catalyst

[0102] The above-prepared 0.5g Zn@ZrO2 and 1g HZSM-5 (Si / Al=25) were fully ground and mixed to obtain a composite catalyst, which was recorded as C-4. The composite catalyst was tableted and granulated into 40-60 mesh particles for subsequent reactions.

[0103] Example 5

[0104] Preparation of zinc oxide-zirconia catalyst

[0105] Preparation of ZrO2 carrier: according to the method of Example 1.

[0106] 1.0g ZrO2 is placed in the lower layer of the quartz tube, and 1.0g zinc oxide is placed in the upper layer. The middle is separated by quartz wool, and hydrogen flows from the upper layer to the lower layer. The tube is treated at 600℃ for 6h in a carbon monoxide atmosphere, and the volume space velocity of carbon monoxide is 7000h -1 The zinc oxide-zirconia catalyst obtained by cooling down the lower layer was taken out and recorded as Zn@ZrO2. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.07:1.

[0107] Preparation of composite catalyst

[0108] The above-prepared 0.5g Zn@ZrO2 and 1.0g HZSM-5 (Si / Al=130) were fully ground and mixed to obtain a composite catalyst, which was recorded as C-5. The composite catalyst was tableted and granulated into 40-60 mesh particles for subsequent reactions.

[0109] Example 6

[0110] The method of Example 1 was followed, except that the catalyst was treated at 550°C for 6 hours under a hydrogen atmosphere to obtain a composite catalyst, which was recorded as C-6. The composite catalyst was pressed into tablets and granulated into 40-60 mesh particles for subsequent reactions. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.03:1.

[0111] Example 7

[0112] The method of Example 1 was followed, except that Ar was used as a carrier gas to obtain a composite catalyst. It was recorded as C-7. The composite catalyst was pressed and granulated into 40-60 mesh particles for subsequent reactions. In the zinc oxide-zirconia catalyst, the mass ratio of zinc oxide to zirconium oxide was 0.005:1.

[0113] Comparative Example 1

[0114] The method of Example 1 was followed, except that 1.0 g of Al2O3 was placed in the lower layer of the quartz tube to obtain a composite catalyst, which was recorded as D-1. The composite catalyst was pressed and granulated into 40-60 mesh particles for subsequent reactions. In the zinc oxide-alumina catalyst, the mass ratio of zinc oxide to alumina was 0.06:1.

[0115] Test Example 1

[0116] 0.5 g of the catalyst prepared in the examples and comparative examples was loaded into a fixed bed reactor with a quartz tube lining (quartz tube inner diameter 8 mm) and an inner diameter of 13 mm. The temperature was raised to 400° C. at 5° C. / min under a hydrogen atmosphere, maintained for 2 hours, and then cooled to 360° C. The reaction raw gas was introduced, the reaction pressure was 3 MPa, the molar ratio of hydrogen to carbon dioxide was 3:1, and the total volume of the raw gas contained 8% of nitrogen (the total volume of the raw gas was the total volume of nitrogen, carbon dioxide and hydrogen), and the volume space velocity of carbon dioxide was 1.63 h / min. -1 The reaction temperature was 360°C for 18 hours. The reaction results are shown in Table 2.

[0117] Table 2

[0118]

[0119] The results in Table 2 show that the composite catalyst prepared by the method of the present invention is applied to the preparation of hydrocarbon compounds by hydrogenation of carbon dioxide, and the selectivity of the target product is high, and the selectivity of C2-C4 olefins in the hydrocarbon product can reach up to 84.9%, and the selectivity of C 5+ The selectivity of hydrocarbons can reach up to 68.2%, and the selectivity of byproduct CH4 is relatively low, reaching a minimum of 4.3%. This shows that the catalyst provided by the present invention has excellent catalytic performance.

[0120] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a zinc oxide-zirconium oxide catalyst, the method comprising: Under the action of carrier gas, zinc oxide is placed upstream of zirconium oxide along the direction of carrier gas introduction, and then heat treatment is performed.

2. The method according to claim 1, wherein: The heat treatment conditions include: temperature of 500-1000°C, preferably 600-800°C; time of 2-10h, preferably 4-6h; Preferably, the volume space velocity of the carrier gas relative to zinc oxide is 2000-8000h -1 , preferably 3000-7000h -1 ; Preferably, the carrier gas is a reducing gas, preferably at least one selected from hydrogen, carbon monoxide and ammonia.

3. The method according to claim 1 or 2, wherein: The amounts of zinc oxide and zirconium oxide used are such that the mass ratio of zinc oxide to zirconium oxide in the prepared zinc oxide-zirconium oxide catalyst is 0.004-0.1, preferably 0.01-0.

08.

4. The method according to any one of claims 1 to 3, wherein: The zinc oxide and the zirconium oxide are placed at intervals; Preferably, an inert filler is placed between the zinc oxide and the zirconium oxide.

5. The zinc oxide-zirconium oxide catalyst prepared by the method according to any one of claims 1 to 4; Preferably, in the zinc oxide-zirconium oxide catalyst, the mass ratio of zinc oxide to zirconium oxide is 0.004-0.1, preferably 0.01-0.

08.

6. A composite catalyst, comprising: The zinc oxide-zirconium oxide catalyst and molecular sieve catalyst according to claim 5; Wherein, based on the total weight of the composite catalyst, the content of the molecular sieve catalyst is 35-95wt%; the content of the zinc oxide-zirconium oxide catalyst is 5-65wt%.

7. The catalyst according to claim 6, wherein Based on the total weight of the composite catalyst, the content of the molecular sieve catalyst is 45-70wt%; the content of the zinc oxide-zirconia catalyst is 30-55wt%; Preferably, the molecular sieve is selected from at least one of CHA structure, MFI structure, MFS structure and MTF structure molecular sieves, preferably selected from at least one of SAPO-34, ZSM-5, ZSM-57 and MCM-35 molecular sieves; Preferably, the silicon to aluminum atomic ratio of the molecular sieve is 0.02-400, preferably 0.2-400.

8. Use of the composite catalyst according to claim 6 or 7 in the preparation of hydrocarbon compounds by hydrogenation of carbon dioxide.

9. A method for preparing hydrocarbon compounds by hydrogenating carbon dioxide, the method comprising: Under the action of a catalyst, carbon dioxide, hydrogen and optionally a diluent gas are contacted and reacted to obtain a target hydrocarbon product; Wherein, the catalyst is the composite catalyst according to claim 6 or 7.

10. The method according to claim 9, wherein: The molar ratio of hydrogen to carbon dioxide is 3-15:1, preferably 3-10:1; Preferably, the diluent gas is selected from at least one of nitrogen, helium, argon and carbon monoxide; Preferably, the molar ratio of the diluent gas to carbon dioxide is 0.1-0.2:1; Preferably, the reaction conditions are: temperature of 250-450°C, preferably 320-450°C; pressure of 0.3-20MPa, preferably 2-15MPa; volume space velocity of carbon dioxide of 0.01-10h -1 , preferably 0.05-8h -1 ; Preferably, the target hydrocarbon product is C2-C4 olefins and / or C 5+ Hydrocarbons.

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