Carbon dioxide hydrogenation catalyst as well as preparation method and application method thereof

Abstract

The invention provides a carbon dioxide hydrogenation catalyst as well as a preparation method and an application method thereof. The catalyst comprises nickel or ruthenium combined with copper-zinc oxide-aluminum oxide, and based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percent of copper is 53-59%, the mass percent of zinc oxide is 23-30%, the mass percent of aluminum oxide is 11-17%, and the mass percent of nickel or ruthenium is 1-20%. The catalyst provided by the invention can resist ammonia poisoning and realize high carbon dioxide hydrogenation activity.

Description

Technical Field

[0001] The present invention relates to a carbon dioxide hydrogenation catalyst, belonging to the fields of energy, chemical industry and environmental protection. More specifically, the present invention relates to a catalyst for preparing C1 chemicals by hydrogenating CO2 that is resistant to ammonia poisoning, and a preparation method and application method thereof. Background Art

[0002] CO2 is the main gas causing the greenhouse effect. How to reduce its emissions and utilize it as a resource is a major challenge facing mankind. CO2 hydrogenation to produce C1 chemicals such as CO or CH4 is one of the most promising CO2 conversion processes in CO2 utilization. Typically, carbon dioxide comes from power plants, steel mills, biomass / waste gasification, biomass / garbage anaerobic digestion and other industrial processes. CO2-rich streams usually contain impurities such as NH3, which adsorbs and blocks the active sites of the catalyst, thereby inhibiting the adsorption / activation of H2; therefore, NH3 is harmful to the RWGS (reverse water gas shift) process and will also poison the catalyst.

[0003] Copper-based catalysts, especially Cu-ZnO-Al2O3, have been widely used in CO2 hydrogenation reactions due to their excellent activity, selectivity and low cost. However, copper-based catalysts are deactivated when exposed to 5% NH3, especially at 300°C. This requires additional gas purification equipment to prevent ammonia from poisoning the catalyst during CO2 conversion and utilization, but this significantly increases the cost of CO2 utilization.

[0004] Up to now, all existing invention patents or documents related to carbon dioxide hydrogenation catalysts have not considered the effect of achieving high CO2 conversion rate and resisting ammonia poisoning in the presence of NH3, which means that there is currently no catalyst invention patent for carbon dioxide hydrogenation to produce C1 chemicals that can resist ammonia poisoning. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] The present invention aims to solve the defects of the prior art and provide a catalyst that can resist ammonia poisoning and achieve high carbon dioxide hydrogenation activity.

[0007] Solutions for solving problems

[0008] The present invention provides the following technical solutions.

[0009] [1] A carbon dioxide hydrogenation catalyst comprising nickel or ruthenium in combination with copper-zinc oxide-aluminum oxide, wherein, based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 53-59%, the mass percentage of zinc oxide is 23-30%, the mass percentage of aluminum oxide is 11-17%, and the mass percentage of nickel or ruthenium is 1-20%.

[0010] [2] The carbon dioxide hydrogenation catalyst according to [1], wherein, based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 55-58%, the mass percentage of zinc oxide is 25-29%, the mass percentage of aluminum oxide is 11-15%, and the mass percentage of nickel or ruthenium is 5-10%.

[0011] [3] A method for preparing a carbon dioxide hydrogenation catalyst according to [1] or [2], comprising the following steps:

[0012] (1) preparing a nickel salt solution or a ruthenium salt solution;

[0013] (2) adding copper-zinc oxide-aluminum oxide into water to prepare a suspension;

[0014] (3) adding the nickel salt solution or the ruthenium salt solution to the suspension to obtain a mixture, and stirring and drying the mixture to obtain a catalyst precursor;

[0015] (4) calcining the dried catalyst precursor to form the carbon dioxide hydrogenation catalyst.

[0016] [4] The preparation method according to [3], wherein the nickel salt solution is one or more of nickel nitrate solution, nickel chloride solution, and nickel acetate solution, and the concentration of the nickel salt solution is 0.1 to 1.8 mg / mL.

[0017] [5] The preparation method according to [3], wherein the ruthenium salt solution is one or more of ruthenium acetate solution, ruthenium nitrosyl nitrate solution, and ruthenium chloride solution, and the concentration of the ruthenium salt solution is 0.1 to 1.8 mg / mL.

[0018] [6] The preparation method according to any one of [3] to [5], wherein in step (3), the mixture is continuously stirred and dried at 60 to 80°C overnight.

[0019] [7] The preparation method according to any one of [3] to [5], wherein in step (4), the dried catalyst precursor is calcined in 5% H2 / N2 at 300-600°C and a heating rate of 1-10°C / min for 1-4 hours.

[0020] [8] A method for preparing C1 chemicals by hydrogenating carbon dioxide, wherein the carbon dioxide hydrogenation catalyst described in [1] or [2] is used in the process of preparing C1 chemicals by hydrogenating carbon dioxide.

[0021] [9] The method according to [8], wherein a mixture of CO2+H2 / N2 or a mixture of 5% NH3 and CO2+H2 / N2 is used as a reaction gas, and a reaction is carried out in a fixed bed reactor equipped with the carbon dioxide hydrogenation catalyst, the reaction temperature is 300-600°C, the reaction pressure is atmospheric pressure, and the reaction volume space velocity GHSV of the reaction feed is 25000h -1 , and the CO product is collected at the reactor outlet.

[0022]

[10] The method according to [9], wherein the selectivity of CO in the total product is above 90%, the reaction gas is a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, and the volume fraction of N2 in the mixed gas is 28-33%; or the reaction gas is a combination of 5% NH3 and a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, wherein NH3 accounts for 5 mol% of the mixed gas and the volume fraction of N2 in the mixed gas is 28%.

[0023] Effects of the Invention

[0024] The catalyst designed in the present invention can resist ammonia poisoning and achieve efficient conversion of CO2, which is of great significance for realizing CO2 utilization.

[0025] Specifically, the main features and advantages of the present invention are as follows:

[0026] 1) The copper, zinc oxide, aluminum oxide, nickel salt or ruthenium salt used to synthesize the catalyst precursor is convenient and easy to obtain, and the copper-based catalyst (copper-zinc oxide-aluminum oxide) itself is also a recognized high-activity catalyst for preparing C1 chemicals from CO2, which ensures the high activity of the catalyst of the present invention.

[0027] 2) The catalyst preparation method is simple and has high activity.

[0028] 3) The obtained catalyst can still maintain high reaction activity under high NH3 concentration, so that the catalyst can be used in harsh environments (containing ammonia).

[0029] 4) The raw materials used in the catalyst of the present invention are easily available, the production conditions are easily controlled, the production cycle is short, there is almost no pollution to the environment, and batch production can be achieved.

[0030] The present invention successfully utilizes CO2 waste gas that affects the climate environment and converts it into C1 products such as CO that can be used for Fischer-Tropsch synthesis or as energy. The catalyst of the present invention can be applied to waste gas streams containing ammonia, and no gas cleaning device is required to pretreat the ammonia-containing waste gas. In addition, the preparation process of the catalyst of the present invention is pollution-free, the preparation process is simple, and the operation cycle is short; the industrial basis of the unit operation involved is mature, and it is easy to carry out large-scale production; and the economic efficiency is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 These are the test results of the catalyst (5% Ni-Cu-ZnO-Al2O3) synthesized in Example 1 in gas streams containing ammonia and in gas streams not containing ammonia.

[0032] Figure 2 These are the test results of the catalyst (5% Ru-Cu-ZnO-Al2O3) synthesized in Example 2 in gas streams containing ammonia and in gas streams not containing ammonia.

[0033] Figure 3 These are the test results of the comparative catalyst (Cu-ZnO-Al2O3) of Comparative Example 1 in ammonia-containing gas streams and ammonia-free gas streams. DETAILED DESCRIPTION

[0034] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0035] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0036] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0037] In this specification, the word "may" includes both performing a certain process and not performing a certain process.

[0038] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0039] In one embodiment, the present invention provides a carbon dioxide hydrogenation catalyst comprising nickel or ruthenium in combination with copper-zinc oxide-aluminum oxide, wherein, based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 53-59%, the mass percentage of zinc oxide is 23-30%, the mass percentage of aluminum oxide is 11-17%, and the mass percentage of nickel or ruthenium is 1-20%.

[0040] In the present invention, the copper-zinc oxide-aluminum oxide (copper-based catalyst) is a known catalyst that can be used for carbon dioxide hydrogenation reaction and can be commercially obtained. The inventive concept of the present invention is to combine nickel or ruthenium into copper-zinc oxide-aluminum oxide to obtain a catalyst that resists ammonia poisoning and achieves efficient CO2 conversion.

[0041] In another embodiment, based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 55-58%, the mass percentage of zinc oxide is 25-29%, the mass percentage of aluminum oxide is 11-15%, and the mass percentage of nickel or ruthenium is preferably 5-10%.

[0042] In the present invention, the mass percentage of nickel or ruthenium is within the above range, which can resist ammonia poisoning and achieve efficient CO2 conversion.

[0043] In one embodiment, the present invention provides a method for preparing the carbon dioxide hydrogenation catalyst of the present invention, comprising the following steps:

[0044] (1) preparing a nickel salt solution or a ruthenium salt solution;

[0045] (2) adding copper-zinc oxide-aluminum oxide into water to prepare a suspension;

[0046] (3) adding the nickel salt solution or the ruthenium salt solution to the suspension to obtain a mixture, and stirring and drying the mixture to obtain a catalyst precursor;

[0047] (4) calcining the dried catalyst precursor to form the carbon dioxide hydrogenation catalyst.

[0048] In step (1) of the present invention, the type of the nickel salt solution is not particularly limited, and those nickel salt solutions commonly used for preparing catalysts can be used. For example, it can be one or more of nickel nitrate solution, nickel chloride solution, and nickel acetate solution, and the concentration of the nickel salt solution is 0.1 to 1.8 mg / mL.

[0049] In the present invention, by making the concentration of the nickel salt solution within the above range, it can be ensured that the catalyst can resist ammonia poisoning and achieve efficient CO2 conversion.

[0050] In step (1) of the present invention, the type of the ruthenium salt solution is not particularly limited, and those ruthenium salt solutions commonly used for preparing catalysts can be used. For example, it can be one or more of ruthenium acetate solution, ruthenium nitrate solution, and ruthenium chloride solution, and the concentration of the ruthenium salt solution is 0.1 to 1.8 mg / mL.

[0051] In the present invention, by making the concentration of the ruthenium salt solution within the above range, it can be ensured that the catalyst can resist ammonia poisoning and achieve efficient CO2 conversion.

[0052] In the present invention, the preparation method of the nickel salt solution or the ruthenium salt solution is not particularly limited. For example, the nickel salt or the ruthenium salt in solid form can be dissolved in a solvent such as water to prepare the nickel salt or the ruthenium salt.

[0053] Preferably, the nickel salt solution or ruthenium salt solution is stirred at room temperature for 2 to 6 hours and set aside.

[0054] In step (2) of the present invention, copper-zinc oxide-aluminum oxide is preferably added to deionized water to prepare a suspension, and stirred at room temperature for 2 to 6 hours for standby use.

[0055] In step (1) and step (2) of the present invention, the amount of nickel salt solution or ruthenium salt solution and copper-zinc oxide-aluminum oxide used is measured based on the mass percentage content of each component in the catalyst of the present invention.

[0056] In the present invention, preferably, in the step (3), the mixture is continuously stirred and dried at 60-80°C, preferably at 80°C overnight.

[0057] In the present invention, preferably, in the step (4), the dried catalyst precursor is calcined in 5% H2 / N2 at 300-600°C and a heating rate of 1-10°C / min for 1-4 hours. Preferably, the dried catalyst precursor is calcined in 5% H2 / N2 at 500°C and a heating rate of 10°C / min for 2 hours.

[0058] In one embodiment, the present invention provides a method for preparing C1 chemicals by hydrogenating carbon dioxide, the method comprising using the carbon dioxide hydrogenation catalyst of the present invention in the process of preparing C1 chemicals by hydrogenating carbon dioxide.

[0059] The production of C1 chemicals such as CO, CH4, and CH3OH by hydrogenation of carbon dioxide is a known production process, and those skilled in the art are familiar with the process conditions.

[0060] In the method of the present invention, CO is preferably prepared by hydrogenating carbon dioxide. Specifically, a mixture of CO2+H2 / N2 or a mixture of 5% NH3 and CO2+H2 / N2 is used as a reaction gas, and a fixed bed reactor equipped with the carbon dioxide hydrogenation catalyst is reacted at a reaction temperature of 300-600°C, a reaction pressure of normal pressure, and a reaction volume space velocity GHSV of 25000h -1 , and the CO product is collected at the reactor outlet.

[0061] In the method of the present invention, the selectivity of CO in the total product is more than 90%, the reaction gas is a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, and the volume fraction of N2 in the mixed gas is 28-33%; or the reaction gas is a combination of 5% NH3 and a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, wherein NH3 accounts for 5 mol% of the mixed gas and the volume fraction of N2 in the mixed gas is 28%.

[0062] Example

[0063] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0064] Example 1: Preparation of 5% nickel-copper-zinc oxide-aluminum oxide catalyst using nickel nitrate hexahydrate

[0065] First, weigh 25 mg of nickel nitrate hexahydrate (Ni(NO3)2·6H2O, purity 99.99%) and dissolve it in 10 ml of deionized water to prepare a nickel salt solution. Add 1 g of copper-zinc oxide-alumina catalyst to 100 mL of water to prepare a suspension. Then, add the nickel salt solution dropwise to 100 ml of copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture is continuously stirred and dried at 80°C overnight. Then, the dried mixture is calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). A nickel-copper-zinc oxide-alumina catalyst is obtained.

[0066] Example 2: Preparation of 5% ruthenium-copper-zinc oxide-aluminum oxide catalyst using ruthenium nitrate

[0067] First, measure 3 ml of ruthenium nitrosyl nitrate (Ru(NO)(NO3) x (OH) y, x+y=3, 0.15g / LRu) was dissolved in 10 ml of deionized water to prepare a ruthenium salt solution. 1g of copper-zinc oxide-alumina catalyst was added to 100mL of water to prepare a suspension. Then the ruthenium salt solution was added dropwise to 100 ml of copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture was continuously stirred and dried at 80°C overnight. Then, the dried mixture was calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). A ruthenium-copper-zinc oxide-alumina catalyst was obtained.

[0068] Example 3: Preparation of 10% nickel-copper-zinc oxide-aluminum oxide catalyst using nickel nitrate hexahydrate

[0069] First, weigh 50 mg of nickel nitrate hexahydrate (Ni(NO3)2·6H2O, purity 99.99%) and dissolve it in 10 ml of deionized water to prepare a nickel salt solution. Add 1 g of copper-zinc oxide-alumina catalyst to 100 mL of water to prepare a suspension. Then, add the nickel salt solution dropwise to 100 ml of copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture is continuously stirred and dried at 80°C overnight. Then, the dried mixture is calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). A nickel-copper-zinc oxide-alumina catalyst is obtained.

[0070] Example 4: Preparation of 10% Ruthenium-Copper-Zinc Oxide-Aluminum Oxide Catalyst Using Ruthenium Nitrate

[0071] First, measure 6 ml of ruthenium nitrosyl nitrate (Ru(NO)(NO3) x (OH) y , x+y=3, 0.15g / LRu) was dissolved in 10 ml of deionized water to prepare a ruthenium salt solution. 1g of copper-zinc oxide-alumina catalyst was added to 100mL of water to prepare a suspension. Then the ruthenium salt solution was added dropwise to 100 ml of copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture was continuously stirred and dried at 80°C overnight. Then, the dried mixture was calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). A ruthenium-copper-zinc oxide-alumina catalyst was obtained.

[0072] Example 5: Preparation of 5% nickel-copper-zinc oxide-aluminum oxide catalyst using nickel acetate

[0073] First, weigh 212 mg of nickel acetate (NiC4H6O4·4H2O, purity 99.9%) and dissolve it in 10 ml of deionized water to prepare a nickel salt solution. Add 1 g of copper-zinc oxide-aluminum oxide catalyst to 100 mL of water to prepare a suspension. Then, add the nickel salt solution dropwise to 100 ml of copper-zinc oxide-aluminum oxide suspension to obtain a mixture. The obtained mixture is continuously stirred and dried overnight at 80° C. Then, the dried mixture is calcined at 500° C. for 2 hours (heating rate 10° C. / min) in 5% H2 / N2. A nickel-copper-zinc oxide-aluminum oxide catalyst is obtained.

[0074] Example 6: Preparation of 5% ruthenium-copper-zinc oxide-aluminum oxide catalyst using ruthenium acetate

[0075] First, weigh 114 mg of ruthenium acetate (C 14 H 21 O 15 Ru3, 99.95%) was dissolved in 10 ml of deionized water to prepare a ruthenium salt solution. 1 g of copper-zinc oxide-alumina catalyst was added to 100 ml of water to prepare a suspension. The ruthenium salt solution was then added dropwise to 100 ml of the copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture was continuously stirred and dried overnight at 80°C. Then, the dried mixture was calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). A ruthenium-copper-zinc oxide-alumina catalyst was obtained.

[0076] Example 7: Preparation of 5% nickel-copper-zinc oxide-aluminum oxide catalyst using nickel chloride

[0077] First, weigh 202 mg of nickel chloride (NiCl2·6H2O, purity 99.9%) and dissolve it in 10 ml of deionized water to prepare a nickel salt solution. Add 1 g of copper-zinc oxide-alumina catalyst to 100 ml of water to prepare a suspension. Then, add the nickel salt solution dropwise to 100 ml of copper-zinc oxide-alumina suspension to obtain a mixture. The obtained mixture is continuously stirred and dried overnight at 80°C. Then, the dried mixture is calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). Obtain a nickel-copper-zinc oxide-alumina catalyst.

[0078] Example 8: Preparation of 5% ruthenium-copper-zinc oxide-aluminum oxide catalyst using ruthenium chloride

[0079] First, weigh 187 mg of ruthenium chloride (RuCl3, 45-55%) and dissolve it in 10 ml of deionized water to prepare a ruthenium salt solution. Add 1 g of copper-zinc oxide-aluminum oxide catalyst to 100 mL of water to prepare a suspension. Then, add the ruthenium salt solution dropwise to 100 ml of copper-zinc oxide-aluminum oxide suspension to obtain a mixture. The obtained mixture is continuously stirred and dried overnight at 80°C. Then, the dried mixture is calcined at 500°C for 2 hours in 5% H2 / N2 (heating rate 10°C / min). Obtain ruthenium-copper-zinc oxide-aluminum oxide catalyst.

[0080] Comparative Example 1: A commercially available copper-zinc oxide-aluminum oxide catalyst was used as a comparative catalyst.

[0081] Table 1 below shows the ICP-OES test results of the examples and comparative catalysts.

[0082] Table 1 ICP-OES test results of Examples 1 and 2 and comparative catalysts

[0083]

[0084] Catalyst Evaluation Methods

[0085] In the present invention, the reaction volume space velocity is defined as the volume flow rate of the reaction gas raw material (base) entering the reaction system per hour divided by the volume of the catalyst, expressed as GHSV, and the unit is h -1 .

[0086] Gas analyzer: Gasboard3000

[0087] Can measure N2, H2, CO2, CO, CH4.

[0088] Application of catalyst (hydrogenation of carbon dioxide to produce CO)

[0089] 50 mg of the catalysts in the above examples and comparative examples were placed in the constant temperature zone of the fixed bed reactor. Before the reaction, the catalyst was reduced online, the reduction temperature was 500°C, the pressure was normal pressure, the reducing gas was H2, and the reduction time was 2 hours. After the reduction was completed, the temperature controller was adjusted to make the reaction temperature reach 300-600°C, the flow rate of the mass flowmeter was adjusted to 60 mL / min (standard conditions), and the reaction was started when the temperature was stable. The product was analyzed online, and samples were taken once every minute.

[0090] Table 2 shows the performance results of the catalysts of the embodiments and comparative examples for the carbon dioxide hydrogenation reaction, as follows. The reaction conditions in Table 1 are reaction temperature of 300-600°C, reaction pressure of normal pressure, raw gas molar composition: CO2 / H2 / N2 / NH3=20 / 20 / 17 / 3 or CO2 / H2 / N2=20 / 20 / 20, reaction volume space velocity of 25000h -1 .

[0091] Table 2

[0092]

[0093] It can be seen from Table 2 that the catalyst of the present invention can still maintain high CO2 conversion activity under reaction gas conditions with a molar ammonia content of up to 5% (in the presence of ammonia), which is an effect that existing carbon dioxide hydrogenation catalysts cannot achieve.

[0094] Figure 1 and Figure 2 In the figure, the area where the yellow circle is located represents the state without ammonia, the area where the red circle is located represents the state with 5% NH3, and the area where the blue circle is located represents the state without ammonia. The combination of the yellow-red-blue circle area represents the CO2 conversion rate (black straight line) and CO selectivity (circle) achieved by the catalyst of the present invention when the catalyst is changed from the state without ammonia to the state with 5% NH3, and then to the state when the introduction of NH3 is stopped, that is, the state without ammonia is restored.

[0095] Depend on Figure 1 and Figure 2 It can be seen that in the process of carbon dioxide hydrogenation, the catalyst of the present invention has a stable CO2 conversion rate within the reaction temperature range of 300-600° C. Even when 5% NH3 is introduced, the CO2 conversion rate achieved by the catalyst of the present invention is equivalent to the CO2 conversion rate in the absence of ammonia.

[0096] Figure 3 The medium dark green is the performance of the Cu-ZnO-Al2O3 catalyst in a gas stream containing 5% NH3, and the red column is the performance of the Cu-ZnO-Al2O3 catalyst in a gas stream without NH3. It can be seen that by comparing the red column (no ammonia condition) and the dark green column (5% NH3), the deactivation of the Cu-ZnO-Al2O3 catalyst in a gas stream with 5% NH3 at 300°C is most obvious. The Cu-ZnO-Al2O3 catalyst is also deactivated in a gas stream with 5% NH3 at 400-600°C.

[0097] However, it can be seen from Table 2 that the catalyst of the present invention is not deactivated in a 5% NH3 gas flow, and the catalysts of the present invention in Examples 3 to 8 also achieve the effects shown in Table 2.

[0098] This shows that the catalyst of the present invention has good reaction stability and can adapt to harsh reaction environments compared to the known copper-zinc oxide-aluminum oxide catalyst. The catalyst of the present invention is used for the reaction of hydrogenating carbon dioxide to prepare C1 chemicals. The process is simple and suitable for industrial scale-up production. At the same time, the preparation method is environmentally friendly.

[0099] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0100] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A carbon dioxide hydrogenation catalyst, characterized in that Contains nickel or ruthenium in combination with copper-zinc oxide-aluminum oxide. Based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 53-59%, the mass percentage of zinc oxide is 23-30%, the mass percentage of aluminum oxide is 11-17%, and the mass percentage of nickel or ruthenium is 1-20%.

2. The carbon dioxide hydrogenation catalyst according to claim 1, characterized in that Based on the total mass of the carbon dioxide hydrogenation catalyst, the mass percentage of copper is 55-58%, the mass percentage of zinc oxide is 25-29%, the mass percentage of aluminum oxide is 11-15%, and the mass percentage of nickel or ruthenium is 5-10%.

3. A method for preparing a carbon dioxide hydrogenation catalyst according to claim 1 or 2, characterized in that The following steps are involved: (1) preparing a nickel salt solution or a ruthenium salt solution; (2) adding copper-zinc oxide-aluminum oxide into water to prepare a suspension; (3) adding the nickel salt solution or the ruthenium salt solution to the suspension to obtain a mixture, and stirring and drying the mixture to obtain a catalyst precursor; (4) calcining the dried catalyst precursor to form the carbon dioxide hydrogenation catalyst.

4. The preparation method according to claim 3, characterized in that: The nickel salt solution is one or more of nickel nitrate solution, nickel chloride solution, and nickel acetate solution, and the concentration of the nickel salt solution is 0.1-1.8 mg / mL.

5. The preparation method according to claim 3, characterized in that: The ruthenium salt solution is one or more of ruthenium acetate solution, ruthenium nitrosyl nitrate solution, and ruthenium chloride solution, and the concentration of the ruthenium salt solution is 0.1-1.8 mg / mL.

6. The preparation method according to any one of claims 3 to 5, characterized in that: In the step (3), the mixture is continuously stirred and dried at 60-80° C. overnight.

7. The preparation method according to any one of claims 3 to 5, characterized in that In the step (4), the dried catalyst precursor is calcined in 5% H2 / N2 at 300-600°C and a heating rate of 1-10°C / min for 1-4 hours.

8. A method for preparing C1 chemicals by hydrogenating carbon dioxide, characterized in that: The carbon dioxide hydrogenation catalyst according to claim 1 or 2 is used in a process for preparing C1 chemicals by hydrogenating carbon dioxide.

9. The method according to claim 8, characterized in that A mixture of CO2+H2 / N2 or a mixture of 5% NH3 and CO2+H2 / N2 is used as a reaction gas and reacted in a fixed bed reactor equipped with the carbon dioxide hydrogenation catalyst. The reaction temperature is 300-600°C, the reaction pressure is normal pressure, and the reaction volume space velocity GHSV of the reaction feed is 25000h -1 , and the CO product is collected at the reactor outlet.

10. The method according to claim 9, characterized in that The selectivity of CO in the total product is above 90%, the reaction gas is a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, and the volume fraction of N2 in the mixed gas is 28-33%; or the reaction gas is a combination of 5% NH3 and a CO2+H2 / N2 mixed gas with a molar ratio of CO2:H2=1:1, wherein NH3 accounts for 5 mol% of the mixed gas and the volume fraction of N2 in the mixed gas is 28%.

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