Fe-based alloy carbide, preparation method thereof and application of Fe-based alloy carbide in carbon dioxide hydrogenation to produce ethanol and olefin

Abstract

This invention provides an Fe-based alloy carbide catalyst, obtained by coupling an FeCo alloy carbide catalyst and a CuZnAl catalyst. This application also provides a method for preparing the Fe-based alloy carbide catalyst and its applications. By optimizing the composition of the multifunctional catalyst and the coupling mode between different catalytically active components, this invention balances the C-O bond activation and C-C bond coupling processes in the CO2 hydrogenation reaction, achieving a direct, one-step, highly selective synthesis of ethanol from CO2 and the co-production of olefins. The CO2 conversion rate reaches 51.1%, the ethanol selectivity reaches 38.2%, and high-value-added olefins are produced simultaneously, realizing the highly efficient synergistic effect between different catalytically active components. This invention opens up a new catalytic reaction pathway for the production of ethanol and olefins from CO2 hydrogenation, with significant economic and social value.

Description

Technical Field

[0001] This invention relates to the field of CO2 hydrogenation catalyst technology, and in particular to an Fe-based alloy carbide catalyst, its preparation method and its application. Background Technology

[0002] As living standards improve in many countries, excessive consumption of fossil fuels such as coal, natural gas, and oil is rapidly increasing. To meet current energy demands (82% of total energy needs), large quantities of coal, oil, and natural gas are burned daily, resulting in significant annual CO2 emissions. According to recent climate reports, global average temperatures are projected to rise by more than 2°C by 2050 and by more than 4°C by 2100. Therefore, to stabilize atmospheric CO2 levels, it is essential not only to reduce CO2 emissions but also to utilize CO2 effectively. As an abundant, inexpensive, non-toxic, and renewable carbon source, CO2 has received widespread attention in many fields in recent years.

[0003] Directly converting CO2 into high-value-added chemicals can alleviate environmental problems and explore new concepts and opportunities for industrial manufacturing. In recent years, bifunctional catalysts have been used to catalyze the hydrogenation of CO2 to C... 2+ Significant progress has been made in hydrocarbon products such as light olefins, aromatics, and gasoline. However, the direct synthesis of ethanol from CO2 via hydrogenation, along with the co-production of olefins, remains a major challenge as another high-value chemical.

[0004] Ethanol, a common substance in chemical production, plays an important role in industrial production and our daily lives. It is used as a fuel additive in many countries, such as the United States, Canada, Brazil, and Sweden. Developing countries like China are also beginning to promote ethanol gasoline. These short-chain alcohols are also used as solvents or starting agents in many chemical products. Due to the world's growing population, the demand for these resources is expected to increase dramatically in the near future.

[0005] Currently, ethanol is mainly produced through the fermentation of sugars from agricultural products such as potatoes, corn, and sugarcane. The large-scale consumption of these agricultural products further exacerbates food shortages. At the same time, the substantial investment required for product separation processes hinders the widespread industrialization of this technology.

[0006] Therefore, proposing effective solutions to the above problems and conducting in-depth research on the underlying mechanisms, constructing an efficient catalytic network for the co-production of olefins from CO2 hydrogenation, while taking into account both CO2 conversion rate and ethanol selectivity, and obtaining excellent single-pass ethanol yield, is the current industrial development trend for the co-production of olefins from CO2 hydrogenation and is also a bottleneck that we urgently need to overcome. Summary of the Invention

[0007] The technical problem solved by this invention is to provide an Fe-based alloy carbide catalyst that can be used for the hydrogenation of CO2 to produce ethanol and olefins, with high CO2 conversion and ethanol selectivity.

[0008] In view of this, this application provides an Fe-based alloy carbide catalyst, which is obtained by coupling an FeCo alloy carbide catalyst and a CuZnAl catalyst;

[0009] The FeCo alloy carbide catalyst is composed of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide, and the CuZnAl catalyst is composed of CuZnAl active component and potassium ions supported on the CuZnAl active component.

[0010] Preferably, the mass ratio of the FeCo alloy carbide catalyst to the CuZnAl catalyst is 1:(0-3) and ≠0.

[0011] Preferably, in the FeCo alloy carbide catalyst, the sodium ion loading is 0.1–5 wt%; and in the CuZnAl catalyst, the potassium ion loading is 0.1–10 wt%.

[0012] Preferably, the molar ratio of Fe to Co in the FeCo alloy carbide catalyst is (1-5):1.

[0013] This application also provides a method for preparing the Fe-based alloy carbide catalyst, including:

[0014] FeCo precursor and CuZnAl catalyst are mixed, and then successively ground, extruded and crushed to obtain Fe-based alloy precursor;

[0015] The Fe-based alloy precursor was reduced with hydrogen and then reacted in reaction gases H2 and CO2 to obtain an Fe-based alloy carbide catalyst.

[0016] Preferably, the preparation method of the FeCo alloy carbide catalyst includes the following steps:

[0017] The iron source, cobalt source, and water are mixed to obtain the initial metal solution;

[0018] Sodium carbonate and water are mixed to obtain a sodium carbonate solution;

[0019] The initial metal solution and the sodium carbonate solution were mixed, aged, dried, and then heat-treated to obtain the FeCo alloy precursor.

[0020] The FeCo alloy precursor was impregnated in a sodium ion solution, then mixed with a CuZnAl catalyst, and then successively ground, extruded and crushed to obtain the Fe-based alloy precursor.

[0021] The Fe-based alloy precursor was reduced with hydrogen and then reacted in situ in the reaction of CO2 and H2 to obtain the FeCo alloy carbide catalyst.

[0022] Preferably, the preparation method of the CuZnAl catalyst includes the following steps:

[0023] A copper source, zinc source, aluminum source and urea are mixed in water and aged to obtain a CuAlZn precursor;

[0024] The CuZnAl precursor was calcined to obtain the CuZnAl active component;

[0025] The CuZnAl active component was impregnated in a potassium ion solution to obtain a CuZnAl catalyst.

[0026] Preferably, in the initial metal solution, the concentration of the iron source is 1-5 mol / L, and the concentration of the cobalt source is 0.5-2 mol / L; in the sodium carbonate solution, the concentration of sodium carbonate is 1-3 mol / L; the pH after mixing is 7-10; the aging temperature is 50-100℃, and the time is 10-24 h; the heat treatment temperature is 300-500℃, and the time is 2-6 h; the sodium ion solution is an aqueous solution of anhydrous sodium carbonate.

[0027] Preferably, the mixing temperature is 50-100℃ and the time is 1-5h, the aging time is 10-24h, and the calcination temperature is 300-600℃ and the time is 1-5h.

[0028] This application also provides the application of the Fe-based alloy carbide or the prepared Fe-based alloy carbide as a catalyst in the synthesis of ethanol from CO2 and the co-production of olefins.

[0029] This application provides a Fe-based alloy carbide catalyst, which is obtained by coupling an FeCo alloy carbide catalyst and a CuZnAl catalyst. The FeCo alloy carbide catalyst consists of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide, while the CuZnAl catalyst consists of a CuZnAl active component and potassium ions supported on the CuZnAl active component. The FeCo alloy carbide catalyst provided in this application facilitates C-C coupling in the carbon dioxide hydrogenation reaction, promoting carbon chain growth, while the CuZnAl catalyst can increase the coverage of oxygen-containing intermediates at the catalytic interface in the carbon dioxide hydrogenation reaction, increasing the formation of C-C. 2+ The probability of producing alcohol synthesis intermediates; therefore, the Fe-based alloy carbide catalyst of this application, when applied to the production of ethanol and olefins by CO2 hydrogenation, exhibits high CO2 conversion and ethanol selectivity. Attached Figure Description

[0030] Figure 1 The image shows the XRD pattern of the Fe-based alloy carbide catalyst after the CO2 hydrogenation reaction. Detailed Implementation

[0031] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0032] In view of the existing technology's need for CO2 hydrogenation to ethanol and co-production of olefins, this application provides a Fe-based alloy carbide catalyst, which is obtained by introducing and coupling FeCo alloy carbide catalyst and CuZnAl catalyst, and its application in CO2 hydrogenation has good catalytic effect. Specifically, the embodiments of this invention disclose a Fe-based alloy carbide catalyst, which is obtained by coupling FeCo alloy carbide catalyst and CuZnAl catalyst;

[0033] The FeCo alloy carbide catalyst is composed of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide, and the CuZnAl catalyst is composed of CuZnAl active component and potassium ions supported on the CuZnAl active component.

[0034] In the Fe-based alloy carbide catalyst provided in this application, the FeCo alloy carbide catalyst is composed of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide. The molar ratio of Fe to Co in the FeCo alloy carbide is (1-5):1, specifically (2-4):1. The sodium ion loading in the FeCo alloy carbide catalyst is 0.1-5 wt%, specifically 1-3 wt%. The Na ions loaded in the FeCo alloy carbide catalyst can avoid excessive hydrogenation during the reaction process and also facilitate the carburization of the FeCo precursor to form iron-cobalt alloy carbides.

[0035] The CuZnAl catalyst consists of a CuZnAl active component and potassium ions supported on the CuZnAl active component. The potassium ion loading in the CuZnAl catalyst is 0.1–10 wt%, specifically 1–7 wt%. This potassium ion loading in the CuZnAl catalyst helps prevent over-hydrogenation during the hydrogenation reaction.

[0036] In this application, the mass ratio of the FeCo alloy carbide catalyst to the CuZnAl catalyst is 1:(0-3) and ≠0. Specifically, the mass ratio of the FeCo alloy carbide catalyst to the CuZnAl catalyst is 1:(1-3).

[0037] In this invention, coupling refers to the binding mode between two components in a multifunctional catalyst.

[0038] This application also provides a method for preparing an Fe-based alloy carbide catalyst, comprising:

[0039] FeCo precursor and CuZnAl catalyst are mixed, and then successively ground, extruded and crushed to obtain Fe-based alloy precursor;

[0040] The Fe-based alloy precursor was reduced with hydrogen and then reacted in reaction gases H2 and CO2 to obtain an Fe-based alloy carbide catalyst.

[0041] In the preparation process of Fe-based alloy carbide catalysts, this application first requires the preparation of FeCo precursor and CuZnAl catalyst. Specifically, the preparation of the FeCo precursor is as follows:

[0042] The iron source, cobalt source, and water are mixed to obtain the initial metal solution;

[0043] Sodium carbonate and water are mixed to obtain a sodium carbonate solution;

[0044] The initial metal solution and the sodium carbonate solution were mixed, aged, dried, and then heat-treated to obtain the FeCo alloy precursor.

[0045] The FeCo alloy precursor was impregnated in a sodium ion solution to obtain the FeCo precursor.

[0046] This invention does not have any particular limitation on the source of the above-mentioned FeCo alloy precursor, which can be commercially available or prepared according to methods known to those skilled in the art. This invention preferably uses the co-precipitation method for preparation, and more preferably uses the following method:

[0047] Ferric nitrate hexahydrate and cobalt nitrate hexahydrate were dissolved in deionized water to make the concentrations of ferric and cobalt 1–4 mol / L, respectively. -1 (more preferably 3 mol L) -1 ) and 0.5–2 mol L -1 (more preferably 1 mol L) -1 Sodium carbonate is dissolved in deionized water to a concentration of 1–3 mol / L. -1 (more preferably 2 mol L) -1The two solutions were added dropwise to a beaker at 60–100°C (more preferably 80°C), the pH was maintained at 9 and the mixture was stirred continuously for 2 hours. The powder was then treated at 60–100°C (more preferably 80°C) for 10–24 hours (more preferably 12 hours), and then dried at 60°C overnight. Finally, the powder was treated in air at 300–500°C (more preferably 350°C) for 3–8 hours (more preferably 4 hours) to obtain the FeCo alloy precursor.

[0048] After obtaining the FeCo alloy precursor, it is impregnated in a sodium ion solution to obtain the FeCo precursor, specifically an aqueous solution of sodium carbonate. The FeCo precursor is an FeCo alloy oxide with sodium ions loaded on its surface.

[0049] The present invention does not have any particular limitation on the source of the above-mentioned CuZnAl active component, which can be commercially available or prepared by methods known to those skilled in the art. The present invention preferably uses the co-precipitation method for preparation, and more preferably uses the following method:

[0050] A copper source compound, a zinc source compound, an aluminum source compound, and urea are mixed in deionized water and kept at 60–100°C (more preferably 95°C) for 1–5 h (more preferably 2 h) under stirring. The mixture is then allowed to stand for aging for 12–24 h (more preferably 24 h) to obtain a CuZnAl catalyst precursor. The CuZnAl catalyst precursor is then calcined in air at 300–600°C (more preferably 350°C) for 1–3 h (more preferably 3 h) to obtain the CuZnAl active component.

[0051] After obtaining the CuZnAl active component, it is impregnated in a solution containing potassium ions, especially an aqueous solution of potassium nitrate, to obtain the CuZnAl catalyst.

[0052] This application then mixes the FeCo precursor and CuZnAl catalyst, followed by extrusion molding, crushing, and sieving to obtain the Fe-based alloy precursor.

[0053] The preferred sieve is a 20-40 mesh sieve.

[0054] In the above process, the FeCo precursor and CuZnAl catalyst are coupled to facilitate the coupling of the FeCo alloy carbide catalyst and the CuZnAl catalyst, and to improve the performance of the oxygen-containing intermediate CH4. x O * The coverage at the catalytic interface, thereby promoting CH x With CH x To improve C-coupling between O*. 2+ Selectivity of alcohols.

[0055] To realize the application of Fe-based alloy carbide catalysts, the Fe-based alloy precursors obtained above need to be further activated by H2 reduction treatment, and then reacted in reaction gases H2 and CO2 to obtain Fe-based alloy carbide catalysts.

[0056] Specifically, the aforementioned Fe-based multifunctional catalyst is loaded into a fixed-bed reactor and then activated to transform the FeCo alloy oxide into the FeCo alloy elemental phase. Subsequently, CO generated from the CO2 + H2 reverse water-gas shift reaction can carburize the FeCo alloy elemental phase into FeCo alloy carbides. At this point, the FeCo alloy carbide catalyst, along with the CuZnAl catalyst, acts as a catalyst to catalyze the hydrogenation of CO2 to synthesize ethanol and co-produce olefins.

[0057] The preferred temperature for the H2 reduction treatment is 200–400°C, more preferably 400°C; the preferred time is 1–6 h, more preferably 4 h; and the preferred flow rate of H2 is 10–100 mL / min, more preferably 60 mL / min.

[0058] This invention also provides the application of the above-mentioned Fe-based alloy carbide catalyst or the Fe-based alloy carbide catalyst prepared by the above preparation method as a catalyst for the direct synthesis of ethanol and co-production of olefins by CO2 hydrogenation.

[0059] This invention provides a method for the direct synthesis of ethanol and co-production of olefins via CO2 hydrogenation, using the above-mentioned Fe-based alloy carbide catalyst or the Fe-based alloy carbide catalyst prepared by the above-mentioned preparation method as the catalyst.

[0060] Specifically, the present invention provides a method for the direct synthesis of ethanol and olefins from CO2 hydrogenation, comprising the following steps: loading an Fe-based alloy carbide catalyst into a fixed-bed reactor, introducing a mixture of CO2 and H2 gas, and performing CO2 hydrogenation to produce ethanol and olefins.

[0061] In this invention, the preferred temperature for the co-production of olefins from CO2 hydrogenation to ethanol is 300–400°C, more preferably 320°C; and the preferred reaction pressure is 3–8 MPa, more preferably 5 MPa.

[0062] Performance tests can be performed during the reaction: gaseous products are analyzed online, while liquid products are collected in a cold trap and analyzed offline.

[0063] Preferably, the catalytic performance test of the Fe-based alloy carbide catalyst is conducted in a fixed-bed reactor. Preferably, a combination of online and offline methods is used to analyze the reaction products. The gas exiting the reactor flows through a cold trap to collect the liquid-phase (oil / water two-phase) products. The composition of the liquid-phase products is analyzed using offline chromatography (Furi GC9790II, FID detector, InerCap-5 column). The tail gas after separating the liquid-phase products is detected by online chromatography (Furi GC9790II) connected to both TCD and FID detectors. The carbon molecular sieve column TDX-1 connected to the TCD detector is used to analyze Ar, CO, CH4, and CO2, while the capillary column HP-PLOT-Q connected to the FID detector is used to analyze hydrocarbons. The pipeline downstream of the reactor is insulated to 180°C with heating tape to prevent condensation of the products in the pipeline.

[0064] Experimental results show that the Fe-based multifunctional catalyst prepared in this invention exhibits a CO2 conversion rate of 51.1%, a CO selectivity of 4.3%, and an ethanol selectivity of 38.2% in the CO2 hydrogenation to ethanol and olefin co-production performance test. This demonstrates that the catalyst can efficiently convert greenhouse gas CO2 into high-value-added chemicals such as ethanol and olefins, with relatively low selectivity for the main byproduct, CO.

[0065] As a further improvement to the technical solution, the yield of ethanol reached 19.5% by continuously optimizing the reaction conditions (temperature, pressure, catalyst mass ratio and space velocity, etc.).

[0066] Any range described in this invention includes end values.

[0067] Unless otherwise specified, all raw materials used in this invention can be purchased commercially, and the equipment used in this invention is based on existing technology in the relevant field.

[0068] This paper presents a Fe-based alloy carbide catalyst, obtained by coupling an FeCo alloy carbide catalyst and a CuZnAl catalyst. The FeCo alloy carbide catalyst consists of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide, while the CuZnAl catalyst consists of a CuZnAl active component and potassium ions supported on the CuZnAl active component. This invention opens up a new route for the co-production of olefins from CO2 hydrogenation to ethanol, using CO2 as a carbon source, turning waste into treasure, and possessing high economic and social value. Furthermore, the preparation process is simple and low-cost, and the catalytic system is original, showing great potential for industrial application.

[0069] To further understand the present invention, the Fe-based alloy carbides, their preparation methods, and applications provided by the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0070] Example 1

[0071] S1. First, FeCo alloy precursors were prepared, then impregnated with Na2CO3 using alkali metals, and dried to prepare FeCo precursors; the specific experimental procedure is as follows:

[0072] 0.15 mol Fe(NO3)3·9H2O (60.6 g) and 0.05 mol Co(NO3)2·6H2O (14.6 g) were dissolved in deionized water to make the concentrations of iron and cobalt 3 mol / L. -1 and 1 mol L -1 Solution A is formed by dissolving 63.5g of Na2CO3 in deionized water to prepare 2mol / L solution. -1 A Na₂CO₃ solution was prepared to form solution B. Both solutions were then added dropwise to an 80℃ beaker, maintaining pH = 9 and stirring continuously for 2 hours. The mixture was then aged at 80℃ for 12 hours. After centrifugation, the product was washed multiple times with deionized water until the Na₂CO₃ was completely removed. + The product was washed and then dried overnight at 60°C in an oven. The product was then treated in air at 350°C for 4 hours to obtain the FeCo alloy precursor.

[0073] 0.069 g of Na2CO3 was used as the Na source and dissolved in 1.8 g of aqueous solution. 1 g of FeCo alloy precursor was impregnated with the solution in an equal volume and dried overnight at 60 °C in a vacuum oven to obtain the FeCo precursor.

[0074] S2. A CuZnAl catalyst was prepared by preparing the CuZnAl active component, followed by alkali metal impregnation with KNO3 and drying. The specific experimental procedure is as follows:

[0075] Take 24.2g Cu(NO3)2·3H2O, 11.9g Zn(NO3)2·6H2O, 5.0g Al(NO3)2·9H2O, and 5g urea, dissolve them in 200mL of deionized water, stir at 95℃ for 2h, and let stand for aging for 24h; after centrifugation, wash the product three times with deionized water, and then dry it overnight at 60℃ in a vacuum oven to obtain the CuZnAl catalyst precursor;

[0076] The obtained precursor was calcined in a tube furnace under air atmosphere. The calcination temperature was controlled at 350℃ for 1 hour. After natural cooling to room temperature, CuZnAl active component was obtained.

[0077] 0.13 g of KNO3 was used as the K source and dissolved in 0.8 g of deionized water. 1 g of CuZnAl active component was impregnated with this solution in equal volume and dried overnight in a vacuum oven at 60 °C to obtain the CuZnAl catalyst.

[0078] S3. The FeCo precursor was coupled with the CuZnAl catalyst to obtain an Fe-based multifunctional catalyst; the specific experimental procedure is as follows:

[0079] Take 0.2g of FeCo precursor and 0.2g of CuZnAl catalyst and grind and mix them. Press the mixed catalyst into tablets under 10MPa, then crush, sieve and granulate to 20-40 mesh.

[0080] Weigh 0.2g of the granulated FeCo precursor and CuZnAl catalyst mixture, mix thoroughly with 1g of quartz sand, and pack into a fixed-bed reactor (inner diameter 6mm); then pack 2g of quartz sand onto the upper part of the catalyst bed to turbulence; reduce with H2 at 400℃ for 4h at an H2 flow rate of 60mL / min; after the temperature drops to the reaction temperature (320℃), switch the gas to the reaction gas (3.04% Ar, 25.6% CO2, 71.36% H2) and raise the pressure to the target pressure (5MPa) under the action of the back pressure valve to start the reaction. The XRD pattern of the catalyst after the reaction is shown below. Figure 1 As shown, by Figure 1 It can be seen that an FeCo alloy carbide catalyst was synthesized in the above reaction process; the catalytic reaction conditions and results are shown in Table 1 below:

[0081] Table 1. Catalytic reaction conditions and results in Example 1 a

[0082]

[0083] a Reaction conditions: 320℃, 5MPa, feed gas (23.75% CO2, 71.25% H2 and 5% Ar), 15mL min -1 Catalyst mass: 0.1g FeCo precursor and 0.1g CuZnAl catalyst.

[0084] b Others: Aldehydes, acids, and other oxygen-containing compounds.

[0085] c Ethanol selectivity: the proportion of ethanol in the total oxygen-containing compounds.

[0086] Example 2

[0087] S1. First, an FeCo alloy precursor was prepared, then impregnated with Na2CO3 using an alkali metal, and dried to prepare the FeCo precursor; the specific experimental procedure is as follows:

[0088] 0.05 mol Fe(NO3)3·9H2O (20.2 g) and 0.05 mol Co(NO3)2·6H2O (14.6 g) were dissolved in deionized water to make the concentrations of iron and cobalt 1 mol / L. -1 and 1 mol L -1 Solution A is formed by dissolving 63.5g of Na2CO3 in deionized water to prepare 2mol / L solution. -1 A Na₂CO₃ solution was prepared to form solution B. Both solutions were then added dropwise to an 80℃ beaker, maintaining pH = 9 and stirring continuously for 2 hours. The mixture was then aged at 80℃ for 12 hours. After centrifugation, the product was washed multiple times with deionized water until the Na₂CO₃ was completely removed. + The product was washed and then dried overnight at 60°C in an oven. The product was then treated in air at 350°C for 4 hours to obtain the FeCo alloy precursor.

[0089] 0.069 g of Na2CO3 was used as the Na source and dissolved in 1.8 g of aqueous solution. 1 g of FeCo alloy precursor was impregnated with the solution in an equal volume and dried overnight at 60 °C in a vacuum oven to obtain the FeCo precursor.

[0090] S2. A CuZnAl catalyst was prepared by preparing the CuZnAl active component, followed by alkali metal impregnation with KNO3 and drying. The specific experimental procedure is as follows:

[0091] Take 24.2g Cu(NO3)2·3H2O, 11.9g Zn(NO3)2·6H2O, 5.0g Al(NO3)2·9H2O, and 5g urea, dissolve them in 200mL of deionized water, stir at 95℃ for 2h, and let stand for aging for 24h; after centrifugation, wash the product three times with deionized water, and then dry it overnight at 60℃ in a vacuum oven to obtain the CuZnAl catalyst precursor;

[0092] The obtained precursor was calcined in a tube furnace under air atmosphere. The calcination temperature was controlled at 350℃ for 1 hour. After natural cooling to room temperature, CuZnAl active component was obtained.

[0093] 0.13 g of KNO3 was used as the K source and dissolved in 0.8 g of deionized water. 1 g of CuZnAl active component was impregnated with this solution in equal volume and dried overnight in a vacuum oven at 60 °C to obtain the CuZnAl catalyst.

[0094] S3. The FeCo precursor was coupled with the CuZnAl catalyst to obtain an Fe-based multifunctional catalyst; the specific experimental procedure is as follows:

[0095] Take 0.2g of FeCo precursor and 0.2g of CuZnAl catalyst and grind and mix them. Press the mixed catalyst into tablets at 10MPa, then crush, sieve and granulate to 20-40 mesh.

[0096] Weigh 0.2g of the granulated FeCo precursor and CuZnAl catalyst mixture, mix thoroughly with 1g of quartz sand, and pack into a fixed-bed reactor (inner diameter 6mm); then pack 2g of quartz sand onto the upper part of the catalyst bed to turbulence; reduce with H2 at 400℃ for 4h, with an H2 flow rate of 60mL / min; after the temperature drops to the reaction temperature (320℃), switch the gas to the reaction gas (3.04% Ar, 25.6% CO2, 71.36% H2) and raise the pressure to the target pressure (5MPa) under the action of the back pressure valve to start the reaction and continue until completion. The catalytic reaction conditions and results are shown in Table 2 below;

[0097] Table 2 Catalytic reaction conditions and results in Example 2 a

[0098]

[0099] a Reaction conditions: 320℃, 5MPa, feed gas (23.75% CO2, 71.25% H2 and 5% Ar), 15mL min -1 Catalyst mass: 0.1g FeCo precursor (1:1) and 0.1g CuZnAl catalyst.

[0100] b Others: Aldehydes, acids, and other oxygen-containing compounds.

[0101] c Ethanol selectivity: the proportion of ethanol in the total oxygen-containing compounds.

[0102] Example 3

[0103] S1. First, FeCo alloy precursors were prepared, then impregnated with Na2CO3 using alkali metals, and dried to prepare FeCo precursors; the specific experimental procedure is as follows:

[0104] 0.25 mol Fe(NO3)3·9H2O (101 g) and 0.05 mol Co(NO3)2·6H2O (14.6 g) were dissolved in deionized water to make the concentrations of iron and cobalt 5 mol / L. -1 and 1 mol L -1 Solution A is formed by dissolving 63.5g of Na2CO3 in deionized water to prepare 2mol / L solution. -1A Na₂CO₃ solution was prepared to form solution B. Both solutions were then added dropwise to an 80℃ beaker, maintaining pH = 9 and stirring continuously for 2 hours. The mixture was then aged at 80℃ for 12 hours. After centrifugation, the product was washed multiple times with deionized water until the Na₂CO₃ was completely removed. + The product was washed and then dried overnight at 60°C in an oven. The product was then treated in air at 350°C for 4 hours to obtain the FeCo alloy precursor.

[0105] 0.069 g of Na2CO3 was used as the Na source and dissolved in 1.8 g of aqueous solution. 1 g of FeCo alloy precursor was impregnated with the solution in an equal volume and dried overnight at 60 °C in a vacuum oven to obtain the FeCo precursor.

[0106] S2. A CuZnAl catalyst was prepared by preparing the CuZnAl active component, followed by alkali metal impregnation with KNO3 and drying. The specific experimental procedure is as follows:

[0107] Take 24.2g Cu(NO3)2·3H2O, 11.9g Zn(NO3)2·6H2O, 5.0g Al(NO3)2·9H2O, and 5g urea, dissolve them in 200mL of deionized water, stir at 95℃ for 2h, and let stand for aging for 24h; after centrifugation, wash the product three times with deionized water, and then dry it overnight at 60℃ in a vacuum oven to obtain the CuZnAl catalyst precursor;

[0108] The obtained precursor was calcined in a tube furnace under air atmosphere, with the calcination temperature controlled at 350℃ for 1 hour. After natural cooling to room temperature, CuZnAl active component was obtained.

[0109] 0.13 g of KNO3 was used as the K source and dissolved in 0.8 g of deionized water. 1 g of CuZnAl active component was impregnated with an equal volume and dried overnight in a vacuum oven at 60 °C to obtain the CuZnAl catalyst.

[0110] S3. The FeCo precursor was coupled with the CuZnAl catalyst to obtain an Fe-based multifunctional catalyst; the specific experimental procedure is as follows:

[0111] Take 0.2g of FeCo precursor and 0.2g of CuZnAl catalyst and grind and mix them. Press the mixed catalyst into tablets under 10MPa, then crush, sieve and granulate to 20-40 mesh.

[0112] Weigh 0.2g of the granulated FeCo precursor and CuZnAl catalyst mixture, mix thoroughly with 1g of quartz sand, and pack into a fixed-bed reactor (inner diameter 6mm); then pack 2g of quartz sand onto the upper part of the catalyst bed to turbulent the flow; reduce with H2 at 400℃ for 4h at an H2 flow rate of 60mL / min; after the temperature drops to the reaction temperature (320℃), switch the gas to the reaction gas (3.04% Ar, 25.6% CO2, 71.36% H2) and raise the pressure to the target pressure (5MPa) under the action of the back pressure valve to start the reaction and continue until completion. The catalytic reaction conditions and results are shown in Table 3 below;

[0113] Table 3. Catalytic reaction conditions and results in Example 3 a

[0114]

[0115] a Reaction conditions: 320℃, 5MPa, feed gas (23.75% CO2, 71.25% H2 and 5% Ar), 15mL min -1 Catalyst mass: 0.1g FeCo(5:1) precursor and 0.1g CuZnAl catalyst.

[0116] b Others: Aldehydes, acids, and other oxygen-containing compounds.

[0117] c Ethanol selectivity: the proportion of ethanol in the total oxygen-containing compounds.

[0118] Comparative Example 1

[0119] S1. First, FeCo alloy precursors were prepared, then impregnated with Na2CO3 using alkali metals, and dried to prepare FeCo precursors; the specific experimental procedure is as follows:

[0120] 0.15 mol Fe(NO3)3·9H2O (60.6 g) and 0.05 mol Co(NO3)2·6H2O (14.6 g) were dissolved in deionized water to make the iron and cobalt concentrations 3 mol / L. -1 and 1 mol L -1 Solution A is formed by dissolving 127g of Na₂CO₃ in deionized water to prepare 2mol / L solution. -1 A Na₂CO₃ solution was prepared to form solution B. Both solutions were added dropwise to an 80℃ beaker, maintaining pH = 9 and stirring continuously for 2 hours. The mixture was then aged at 80℃ for 12 hours. After centrifugation, the product was washed multiple times with deionized water until the Na₂CO₃ was completely removed. + The product was washed and then dried overnight in an oven at 60°C. The product was then treated in air at 350°C for 4 hours to obtain the FeCo alloy precursor.

[0121] 0.069 g of Na2CO3 was used as the Na source and dissolved in 1.8 g of aqueous solution. 1 g of FeCo catalyst was impregnated with the solution in an equal volume and dried overnight at 60 °C in a vacuum oven to obtain the FeCo precursor.

[0122] S2. A CuZnAl catalyst was prepared by preparing the CuZnAl active component, followed by alkali metal impregnation with KNO3 and drying. The specific experimental procedure is as follows:

[0123] Take 24.2g Cu(NO3)2·3H2O, 11.9g Zn(NO3)2·6H2O, 5.0g Al(NO3)2·9H2O, and 5g urea, dissolve them in 200mL of deionized water, stir at 95℃ for 2h, and let stand for aging for 24h; after centrifugation, wash the product three times with deionized water, and then dry it overnight at 60℃ in a vacuum oven to obtain the CuZnAl catalyst precursor;

[0124] The obtained precursor was calcined in a tube furnace under air atmosphere. The calcination temperature was controlled at 350℃ for 1 hour. After natural cooling to room temperature, CuZnAl active component was obtained.

[0125] 0.13 g of KNO3 was used as the K source and dissolved in 0.8 g of deionized water. 1 g of CuZnAl was impregnated with this solution in an equal volume and dried overnight in a vacuum oven at 60 °C to obtain the CuZnAl catalyst.

[0126] S3. The FeCo precursor was coupled with the CuZnAl catalyst to obtain an Fe-based multifunctional catalyst; the specific experimental procedure is as follows:

[0127] The FeCo precursor was compressed into tablets at 10 MPa, then crushed, sieved, and granulated to 20-40 mesh.

[0128] The CuZnAl catalyst was pressed into tablets at 10 MPa, then crushed, sieved and granulated to 20-40 mesh.

[0129] 0.1 g of granulated FeCo precursor and 0.1 g of CuZnAl catalyst were weighed and thoroughly mixed with 1 g of silica sand, then packed into a fixed-bed reactor (6 mm inner diameter). Another 2 g of silica sand was placed on top of the catalyst bed to turbulence the flow. H2 reduction was carried out at 400℃ for 4 h at a flow rate of 60 mL / min. After the temperature dropped to the reaction temperature (320℃), the gas was switched to the reaction gas (23.75% CO2, 71.25% H2, and 5% Ar), and the pressure was increased to the target pressure (5 MPa) under the action of a back pressure valve to initiate the reaction. The catalytic reaction conditions and results are shown in Table 4 below.

[0130] Table 4. Catalytic reaction conditions and results in Comparative Example 1 a

[0131]

[0132] a Reaction conditions: 320℃, 5MPa, feed gas (23.75% CO2, 71.25% H2 and 5% Ar), 15mL min -1 Catalyst mass: 0.1g FeCo and 0.1g CuZnAl.

[0133] b Others: Aldehydes, acids, and other oxygen-containing compounds.

[0134] c Ethanol selectivity: the proportion of ethanol in the total oxygen-containing compounds.

[0135] Comparative Example 2

[0136] S1. First, an FeCo alloy precursor was prepared, then impregnated with Na2CO3 using an alkali metal impregnation method, and dried to prepare the FeCo catalyst; the specific experimental procedure is as follows:

[0137] 0.15 mol Fe(NO3)3·9H2O (60.6 g) and 0.05 mol Co(NO3)2·6H2O (14.6 g) were dissolved in deionized water to make the concentrations of iron and cobalt 3 mol / L. -1 and 1 mol L -1 Solution A is formed by dissolving 127g of Na₂CO₃ in deionized water to prepare 2mol / L solution. -1 A Na₂CO₃ solution was prepared to form solution B. Both solutions were added dropwise to an 80℃ beaker, maintaining pH = 9 and stirring continuously for 2 hours. The mixture was then aged at 80℃ for 12 hours. After centrifugation, the product was washed multiple times with deionized water until the Na₂CO₃ was completely removed. + The product was washed and then dried overnight at 60°C in an oven. The product was then treated in air at 350°C for 4 hours to obtain the FeCo alloy precursor.

[0138] 0.069 g of Na2CO3 was used as the Na source and dissolved in 1.8 g of aqueous solution. 1 g of FeCo alloy precursor was impregnated with the solution in an equal volume and dried overnight at 60 °C in a vacuum oven to obtain the FeCo precursor.

[0139] S2. The specific experimental procedure is as follows:

[0140] The FeCo alloy precursor was pressed into tablets at 10 MPa, then crushed, sieved and granulated to 20-40 mesh.

[0141] 0.1g of granulated FeCo alloy precursor was weighed and thoroughly mixed with 1g of silica sand. This mixture was then packed into a fixed-bed reactor (6mm inner diameter). Another 2g of silica sand was placed on top of the catalyst bed to create turbulence. H2 reduction was carried out at 400℃ for 4h at a flow rate of 60mL / min. After the temperature dropped to the reaction temperature (320℃), the gas mixture was switched to the reaction gas (3.04% Ar, 25.6% CO2, 71.36% H2), and the pressure was increased to the target pressure (5MPa) under the action of a back pressure valve to initiate the reaction. The catalytic reaction conditions and results are shown in Table 5 below.

[0142] Table 5. Catalytic reaction conditions and results in Comparative Example 2 a

[0143]

[0144] a Reaction conditions: 320℃, 5MPa, feed gas (23.75% CO2, 71.25% H2 and 5% Ar), 15mL min -1 Catalyst mass: 0.1g FeCo.

[0145] b Others: Aldehydes, acids, and other oxygen-containing compounds.

[0146] c Ethanol selectivity: the proportion of ethanol in the total oxygen-containing compounds.

[0147] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0148] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An Fe-based alloy carbide catalyst characterized by, The FeCo alloy carbide catalyst is coupled with the CuZnAl catalyst; The FeCo alloy carbide catalyst is composed of FeCo alloy carbide and sodium ions supported on the FeCo alloy carbide, and the CuZnAl catalyst is composed of CuZnAl active component and potassium ions supported on the CuZnAl active component; The preparation method of the CuZnAl catalyst comprises the following steps: A copper source, a zinc source, an aluminum source and urea are mixed in water, and after aging, a CuAlZn precursor is obtained; The CuZnAl precursor is calcined to obtain a CuZnAl active component; The CuZnAl active component is impregnated in a potassium ion solution to obtain a CuZnAl catalyst. The preparation method of the Fe-based alloy carbide catalyst comprises: An iron source, a cobalt source and water are mixed to obtain an initial metal solution; Sodium carbonate and water are mixed to obtain a sodium carbonate solution; The initial metal solution and the sodium carbonate solution are mixed, aged, dried and then heat treated to obtain an FeCo alloy precursor; The FeCo alloy precursor is impregnated in a sodium ion solution, mixed with the CuZnAl catalyst, and then sequentially subjected to grinding, extrusion molding and crushing to obtain an Fe-based alloy precursor; The Fe-based alloy precursor is reduced by hydrogen and then subjected to in-situ reaction in a CO2 and H2 reaction to obtain an Fe-based alloy carbide catalyst.

2. The Fe-based alloy carbide catalyst according to claim 1, characterized by, The mass ratio of the FeCo alloy carbide catalyst to the CuZnAl catalyst is 1:(0-3) and ≠0.

3. The Fe-based alloy carbide catalyst according to claim 1, characterized by, In the FeCo alloy carbide catalyst, the loading amount of sodium ions is 0.1-5wt%; in the CuZnAl catalyst, the loading amount of potassium ions is 0.1-10wt%.

4. The Fe-based alloy carbide catalyst according to claim 1, characterized by, In the FeCo alloy carbide catalyst, the molar ratio of Fe to Co is (1-5):

1.

5. The method of producing the Fe-based alloy carbide catalyst according to claim 1, characterized by, The preparation method of the CuZnAl catalyst comprises the following steps: A copper source, a zinc source, an aluminum source and urea are mixed in water, and after aging, a CuAlZn precursor is obtained; The CuZnAl precursor is calcined to obtain a CuZnAl active component; The CuZnAl active component is impregnated in a potassium ion solution to obtain a CuZnAl catalyst. The preparation method of the Fe-based alloy carbide catalyst comprises: An iron source, a cobalt source and water are mixed to obtain an initial metal solution; Sodium carbonate and water are mixed to obtain a sodium carbonate solution; The initial metal solution and the sodium carbonate solution are mixed, aged, dried and then heat treated to obtain an FeCo alloy precursor; The FeCo alloy precursor is impregnated in a sodium ion solution, mixed with the CuZnAl catalyst, and then sequentially subjected to grinding, extrusion molding and crushing to obtain an Fe-based alloy precursor; The Fe-based alloy precursor is reduced by hydrogen and then subjected to in-situ reaction in a CO2 and H2 reaction to obtain an Fe-based alloy carbide catalyst; The preparation method of the CuZnAl catalyst comprises the following steps: A copper source, a zinc source, an aluminum source and urea are mixed in water, and after aging, a CuAlZn precursor is obtained; The CuZnAl precursor is calcined to obtain a CuZnAl active component; The CuZnAl active component is impregnated in a potassium ion solution to obtain a CuZnAl catalyst.

6. The production method according to claim 5, wherein The concentration of the iron source in the initial metal solution is 1-5 mol / L, and the concentration of the cobalt source is 0.5-2 mol / L; the concentration of the sodium carbonate in the sodium carbonate solution is 1-3 mol / L; in the preparation step of the FeCo alloy precursor, the pH of the mixture is 7-10; the aging temperature is 50-100 ℃, and the time is 10-24 h; the heat treatment temperature is 300-500 ℃, and the time is 2-6 h; and the sodium ion solution is anhydrous sodium carbonate aqueous solution.

7. The preparation method according to claim 5, characterized in that, In the preparation step of the CuZnAl catalyst, the mixing temperature is 50-100 ℃, the time is 1-5 h, the aging time is 10-24 h, the calcination temperature is 300-600 ℃, and the time is 1-5 h.

8. Use of the Fe-based alloy carbide catalyst according to any one of claims 1-4 or the Fe-based alloy carbide catalyst prepared by the preparation method according to any one of claims 5-7 in the synthesis of ethanol and olefins co-produced by CO2 hydrogenation.

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