Fischer-Tropsch synthesis iron-based catalyst and preparation method thereof

Abstract

The invention provides a Fischer-Tropsch synthesis iron-based catalyst, which comprises an Fe element, a Cu element, a K element, SiO2 and M. M is a ternary composite auxiliary agent and is composed of a V element, a B element and an alkaline earth metal element, and the alkaline earth metal element is selected from at least one of a Ba element, a Mg element, a Ca element and a Sr element; wherein when the mass ratio of the Fe element to the V element is 100: (1-5.5), the mass ratio of the Fe element to the B element is 100: (1.5-2.5), and the mass ratio of the Fe element to the alkaline earth metal element is 100: (5.5-10); when the ratio of the Fe element to the V element is 100: (5.5-10), the ratio of the Fe element to the B element is 100: (0.5-1.5), and the ratio of the Fe element to the alkaline earth metal element is 100: (1-5.5). The invention also provides a preparation method of the Fischer-Tropsch synthesis iron-based catalyst. By adding the V-B-alkaline earth metal composite additive combination into the catalyst, the reaction activity of the catalyst is improved, the CO2 selectivity is reduced, and the selectivity of long-chain alpha-olefin is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of Fischer-Tropsch synthesis, in particular to the field of Fischer-Tropsch synthesis catalysts, and specifically to a Fischer-Tropsch synthesis iron-based catalyst and a preparation method thereof. Background Art

[0002] The Fischer-Tropsch synthesis reaction can be carried out by using CO and H under appropriate temperature, pressure and catalyst. 2 Hydrocarbon compounds with different carbon numbers are synthesized, and the products are then processed to obtain fuels and chemicals. Fischer-Tropsch synthesis can be used to achieve energy conversion from coal, natural gas, biomass, etc. to oil through synthesis gas. Producing more high-value-added chemicals through Fischer-Tropsch synthesis is an important way to improve the economic efficiency of Fischer-Tropsch synthesis technology and promote the high-end development of the coal-to-oil industry. Long-chain linear α-olefins (C≥4) are indispensable raw materials for the manufacture of plastics, plasticizers, lubricants and surfactants. The products have high added value, and there is a large gap in the domestic product supply, especially 1-octene and 1-hexene, which mainly rely on imports. Therefore, the use of Fischer-Tropsch synthesis technology, through catalyst design, effectively controlling product selectivity, and realizing the preparation of long-chain linear α-olefins is of great significance and industrial application value.

[0003] The traditional long-chain linear α-olefin production processes mainly include paraffin cracking and ethylene polymerization. Among them, paraffin cracking has been completely discontinued in countries with limited raw wax resources; in countries with abundant wax resources, paraffin cracking to produce α-olefins is still a desirable process route. The ethylene polymerization process for preparing long-chain α-olefins is mainly divided into alkyl aluminum catalyzed ethylene polymerization, nickel complex catalyzed ethylene polymerization, zirconium catalyzed ethylene polymerization and other processes according to the type of catalyst. However, since the raw material of ethylene mainly comes from petroleum, with the shrinking of oil and gas resources worldwide, this production process is also in urgent need of transformation.

[0004] The technology of preparing long-chain α-olefins by using the Fischer-Tropsch synthesis process has gradually attracted the attention of researchers in recent years. Ma et al. prepared Fe-Zn-Na catalyst by coprecipitation method. Under the reaction conditions of 340°C and 2Mpa, the CO conversion rate of the catalyst was about 70%, and long-chain olefins accounted for about 50% of the hydrocarbon products (Angew.Chem.Int.Ed.2016,55,9902-9907). Guo Li et al. (CN106391016A) announced a monodisperse iron-based catalyst for Fischer-Tropsch synthesis, its preparation method and application, which encapsulates iron nanoparticles inside spherical silica to prevent the sintering of iron nanoparticles and avoid the appearance of difficult-to-reducible components. The catalyst was slurry bed at 250°C, 1.0Mpa, 3000h -1 Under the condition of space velocity, CO conversion rate is 42.8%, CH 4Selectivity 4.5%, C5+ selectivity 81.7%, olefin content 63.1%. Liu Zhongwen et al. (CN109534939A) disclosed a method for preparing α-olefins directly from synthesis gas in one step with high selectivity by catalyzing a supported Co-based catalyst. The method prepares the catalyst. The catalyst has a low reaction temperature range of 200-230°C, and the CO single-pass conversion rate can reach up to 76%, CH 4 Selectivity ≤ 8.0%, CO 2 Selectivity ≤ 1.0%, olefin selectivity up to 60%, of which long-chain α-olefins (C ≥ 4) account for 70%. Xiang Hongwei et al. (CN1583259A) disclosed a method for preparing and using a microspherical Fischer-Tropsch synthesis iron-based catalyst, Fe-Ce-Cu-K-SiO prepared by coprecipitation method. 2 Catalyst, in slurry bed at 220℃, 3.0Mpa, 3000h -1 Under the condition of space velocity, CO conversion rate is 69.2%, CH 4 Selectivity is 2.9%, C5+ selectivity is 84.62%, and olefin content is 73%.

[0005] As mentioned above, the existing technology has made some progress in the preparation of long-chain olefins by Fischer-Tropsch synthesis, but the main problems that still exist are: low catalyst reaction activity; low selectivity for long-chain α-olefins (C≥4); and by-product CH 4 and CO 2 The selectivity is too high; the preparation process of some catalysts is complicated and the raw material cost is high; and the catalyst stability is poor and is not suitable for industrial application. Summary of the invention

[0006] In view of the problems existing in the prior art, one of the purposes of the present invention is to provide an iron-based catalyst for Fischer-Tropsch synthesis, which improves the catalyst reaction activity and reduces the CO 2 Another object of the present invention is to provide a method for preparing the Fischer-Tropsch synthesis iron-based catalyst.

[0007] To achieve the purpose, the present invention provides the following technical solutions:

[0008] In one aspect of the present invention, it relates to a Fischer-Tropsch synthesis iron-based catalyst, which comprises Fe element, Cu element, K element, SiO 2and M, wherein M is a ternary composite additive, which is composed of V element, B element and alkaline earth metal element, and the alkaline earth metal element is selected from at least one of Ba element, Mg element, Ca element and Sr element; wherein, by mass ratio, when Fe element:V element=100:1~less than 5.5, Fe element:B element=100:1.5~2.5 (for example, 2.0 or any combination thereof), Fe element:alkaline earth metal element=100:5.5~10 (for example, 6 , 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 or any combination thereof); when Fe element: V element = 100: 5.5-10, Fe element: B element = 100: 0.5-less than 1.5 (for example, 1.0 or any combination thereof), Fe element: alkaline earth metal element = 100: 1-less than 5.5 (for example, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 or any combination thereof).

[0009] In some embodiments of the Fischer-Tropsch synthesis iron-based catalyst of the present invention, the following weight ratios are used: Fe element: Cu element: K element: SiO 2 :M=100:0.2~5 (for example, 0.4, 0.6, 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or any combination thereof):0.5~8 (for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5 or any combination thereof):10~42 (for example, 15, 20, 25, 30, 35, 40 or any combination thereof):6.5~18 (for example, 8, 10, 12, 14, 16 or any combination thereof).

[0010] In another aspect of the present invention, it relates to a method for preparing an iron-based catalyst for Fischer-Tropsch synthesis, which comprises the following steps:

[0011] S1: forming a mixed aqueous solution of a water-soluble salt of the Fe element and a water-soluble salt of the Cu element, preparing a precipitant solution, and adding 0 to 100 wt % (e.g., about 10 wt %, about 20 wt %, about 30 wt %, about 40 wt %, about 50 wt %, about 60 wt %, about 70 wt %, about 80 wt %, about 90 wt %, or any combination of weight ratios) of a silicon source to the precipitant solution;

[0012] S2: contacting the mixed aqueous solution with the precipitant solution to perform a precipitation reaction, and separating the obtained precipitation product after the reaction is completed;

[0013] S3: mixing the precipitation product with the K element precursor aqueous solution and the remaining silicon source to form a mixed slurry and performing slurry treatment to obtain a catalyst precursor slurry; and

[0014] S4: drying and calcining the catalyst precursor slurry;

[0015] The method of adding the V element includes: adding a water-soluble salt of the V element to the mixed aqueous solution and / or the precipitant solution in step S1; or adding a water-soluble salt of the V element to the K element precursor aqueous solution and / or the mixed slurry in step S3;

[0016] The method of adding the B element includes: adding a boron source to the mixed aqueous solution and / or the precipitant solution in step S1; or adding a boron source to the precursor aqueous solution and / or the mixed slurry of the K element in step S3;

[0017] Among them, the method of adding alkaline earth metal elements includes: adding water-soluble salts or hydroxides of alkaline earth metal elements to the mixed aqueous solution of step S1; or preparing water-soluble salts or hydroxides of alkaline earth metal elements into an aqueous solution, and then adding them to the K element precursor aqueous solution and / or mixed slurry of step S3.

[0018] In some embodiments of the preparation method of the present invention, the water-soluble salt of the V element is one or more metavanadates, such as sodium metavanadate or potassium metavanadate.

[0019] In some embodiments of the preparation method of the present invention, the water-soluble salt of the alkaline earth metal element is a nitrate or a hydrate thereof.

[0020] In some embodiments of the preparation method of the present invention, the boron source is one or more of boric acid, metaboric acid, boric oxide, and water-soluble borates. In a preferred embodiment of the preparation method of the present invention, the water-soluble borate is potassium borate and / or sodium borate.

[0021] In some embodiments of the preparation method of the present invention, the water-soluble salt of the Fe element is a nitrate, a hydrochloride or a hydrate of each of Fe. Preferably, in the mixed aqueous solution, the concentration of Fe is 5 to 100 g / L, for example, about 10 g / L, about 20 g / L, about 30 g / L, about 40 g / L, about 50 g / L, about 60 g / L, about 70 g / L, about 80 g / L, about 90 g / L or any combination of concentration intervals.

[0022] In some embodiments of the preparation method of the present invention, the water-soluble salt of the Cu element is Cu nitrate, Cu hydrochloride or their respective hydrates.

[0023] In some embodiments of the preparation method of the present invention, the precipitant is selected from one or more of sodium carbonate, ammonia water, ammonium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate.

[0024] In a preferred embodiment of the preparation method of the present invention, the concentration of the precipitant is 50-150 g / L, for example, it can be about 60 g / L, about 70 g / L, about 80 g / L, about 90 g / L, about 100 g / L, about 110 g / L, about 120 g / L, about 130 g / L, about 140 g / L or any combination of concentration intervals.

[0025] In some embodiments of the preparation method of the present invention, the silicon source is selected from one or more of potassium silicate solution, sodium silicate solution, and silica sol solution, wherein SiO 2 The concentration is 10-50 wt %, for example, about 20 wt %, about 30 wt %, about 40 wt % or any combination of concentration intervals.

[0026] In some embodiments of the preparation method of the present invention, the K element precursor is one or more of potassium nitrate, potassium carbonate, potassium bicarbonate, potassium chloride, and potassium silicate.

[0027] In some embodiments of the preparation method of the present invention, in the step S2, the precipitation temperature of the precipitation reaction is 5 to 95°C (for example, it can be about 20°C, about 40°C, about 60°C, about 80°C, or any combination of temperature intervals), the precipitation time is 5 to 100 min (for example, it can be about 5 min, about 20 min, about 40 min, about 60 min, about 80 min, or any combination of time intervals), and the pH value during the precipitation process is controlled at 5 to 10 (for example, it can be about 6, about 7, about 8, about 9, or any combination of pH value intervals).

[0028] In some embodiments of the preparation method of the present invention, in the step S3, the slurrying temperature of the slurrying treatment is 10-80°C (for example, it can be about 20°C, about 30°C, about 40°C, about 50°C, about 60°C, about 70°C, or any combination of temperature intervals), the slurrying time is 10-80 min (for example, it can be about 20 min, about 30 min, about 40 min, about 50 min, about 60 min, about 70 min, or any combination of time intervals), and the concentration of the slurry during the slurrying treatment is controlled to be 5-40wt% (for example, it can be about 10wt%, about 15wt%, about 20wt%, about 25wt%, about 30wt%, about 35wt%, or any combination of concentration intervals).

[0029] In some embodiments of the preparation method of the present invention, in the step S4, the drying includes the following process: first, the catalyst precursor slurry is spray-dried, and the obtained powder is dried in an air atmosphere at 110-300°C (for example, it can be about 150°C, about 200°C, about 250°C, which can be any combination of temperature intervals) for 1-12h (for example, it can be about 2h, 4h, 6h, 8h, 10h or can be any combination of time intervals); preferably, the hot air inlet temperature of the spray drying is 180-400°C (for example, it can be about 240°C, about 300°C, about 360°C or can be any combination of temperature intervals), and the exhaust outlet temperature is 100-220°C (for example, it can be about 140°C, about 160°C, about 180°C, about 200°C or can be any combination of temperature intervals).

[0030] In some embodiments of the preparation method of the present invention, in the step S4, the calcination temperature is 400-600°C (for example, it can be about 450°C, about 500°C, about 550°C, or any combination of temperature intervals), and the calcination time is 1-15h (for example, it can be 2h, 4h, 6h, 8h, 1012h, 14h, or any combination of time intervals).

[0031] The present invention provides a Fe-Cu-K-SiO 2 A Fischer-Tropsch synthesis catalyst and a preparation method thereof are provided with a ternary composite additive of VB-alkaline earth metal (at least one of Mg, Ca, Sr and Ba) as a basic formula. By adding a VB-alkaline earth metal composite additive combination to the catalyst, the electronic synergy of the additive combination is utilized to promote the active center of the catalyst to react with CO and H 2 The dissociation effect of the catalyst improves the reaction activity of the catalyst; strengthens the carburization process of the active phase during the reaction and avoids CO 2 The generation of oxide active centers reduces the CO 2 Selectivity; the secondary adsorption capacity of active relative long-chain α-olefins is reduced, and the selectivity of long-chain α-olefins is improved; in addition, preferably, through the introduction of a ternary composite auxiliary agent and in conjunction with the preparation process of the catalyst, a catalyst matrix with a macroporous structure having an average pore size greater than 18 nm can be constructed, which effectively promotes the rapid diffusion of long-chain α-olefins and further enhances the generation of high value-added long-chain α-olefin products. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be further described below in conjunction with examples. It should be understood that the following examples are only for a better understanding of the present invention and do not mean that the present invention is limited to the following examples.

[0033] Where specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps or conditions in the art can be used. The reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained commercially. The percentages used in the examples and comparative examples of the present invention are all mass percentages unless otherwise specified.

[0034] The test methods used in the present invention include: (1) Catalyst composition: measured by X-ray fluorescence component analyzer (XRF); (2) Catalyst specific surface area (BET): measured by static low-temperature nitrogen adsorption method at 77K. 2 After the adsorption isotherm, BET was calculated using the BET model equation; (3) Pore volume (PV): N measured at 77K 2 The pore volume corresponds to the position of P / P0=0.98-0.99 on the adsorption isotherm. (4) Average pore diameter (PD): calculated according to PD=4*PV / BET.

[0035] I. Preparation Example

[0036] Example 1

[0037] 10kg Fe(NO 3 ) 3 9H 2 O, 137g Cu(NO 3 ) 2 ·3H 2 O and 263g Ba(NO 3 ) 2Dissolve in deionized water to make 50 liters of solution, add 5kg of ammonium carbonate, 1.84kg of silica sol solution with a silica mass concentration of 30% and 33.1g of sodium metavanadate to deionized water to make 40 liters of solution. The mixed solution containing iron, copper and barium is precipitated together with the ammonia silicon solution, the precipitation temperature is 30°C, the precipitation time is 60min, and the pH is controlled at 9.0. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 195g of potassium carbonate and 178g of boric acid are fully dissolved in 1.5kg of deionized water to prepare a K element precursor aqueous solution. The K element precursor aqueous solution is added to the catalyst precursor filter cake for slurrying, and the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 25°C, and the slurrying time is 20min. After the slurrying is completed, a catalyst precursor slurry is obtained. The inlet temperature was controlled at 380°C and the outlet hot air temperature was controlled at 220°C for spray drying, and the spray drying product was collected, and the obtained product was dried at 120°C in an air atmosphere for 12 hours, and calcined at 450°C in an air atmosphere for 5 hours to obtain a finished catalyst, which was recorded as catalyst 1. The component composition, specific surface area (BET), pore volume (PV) and average pore diameter (PD) of the catalyst were measured, and the results are shown in Table 1, the same below.

[0038] Example 2

[0039] 10kg Fe(NO 3 ) 3 9H 2 O, 137g Cu(NO 3 ) 2 ·3H 2 O and 197g Ba(NO 3 ) 2Dissolve in deionized water to make 50 liters of solution, add 4kg of sodium carbonate, 30g of silica sol solution with a silica mass concentration of 20% and 123.6g of potassium metavanadate to deionized water to make 40 liters of solution. The mixed solution containing iron, copper and barium is precipitated together with the ammonia silicon solution, the precipitation temperature is 50°C, the precipitation time is 50min, and the pH is controlled at 8.5. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 12g of potassium carbonate and 138g of boric acid are fully dissolved in 1.5kg of deionized water to prepare a K element precursor aqueous solution. The K element precursor aqueous solution and 660g of silica sol solution with a silica mass concentration of 20% are added to the catalyst precursor filter cake in sequence for slurrying, and the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 30°C, and the slurrying time is 30min. After the slurrying is completed, a catalyst precursor slurry is obtained. The inlet temperature was controlled at 350°C and the outlet hot air temperature was controlled at 160°C for spray drying, and the spray drying product was collected. The obtained product was dried at 150°C in an air atmosphere for 10 h and calcined at 400°C in an air atmosphere for 15 h to obtain a finished catalyst, which was recorded as Catalyst 2.

[0040] Example 3

[0041] 10kg Fe(NO 3 ) 3 9H 2 O, 263g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to prepare 50 liters of solution, and 8 kg of 25% ammonia water and 140 g of potassium silicate solution with a silicon dioxide mass concentration of 20% were added to deionized water to prepare 40 liters of solution. The iron-copper mixed solution was precipitated together with the ammonia-silicon solution at a precipitation temperature of 70°C, a precipitation time of 30 minutes, and a pH of 5.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 104 g of potassium carbonate, 158 g of boric acid and 172 g of sodium metavanadate were fully dissolved in 1.0 kg of deionized water to prepare a K element precursor aqueous solution, and 158 g of Ba(NO 3 ) 2Fully dissolve in 0.5kg deionized water to prepare Ba auxiliary agent aqueous solution. Add 2.63kg of silica sol solution with a silica mass concentration of 20%, Ba auxiliary agent aqueous solution and K element precursor aqueous solution to the catalyst precursor filter cake in sequence for slurrying. Control the mass concentration of the slurry to be 15%, the slurrying temperature to be 50°C, and the slurrying time to be 40min. After the slurrying is completed, the catalyst precursor slurry is obtained. Control the inlet temperature at 320°C and the outlet hot air temperature at 140°C for spray drying, collect the spray drying product, dry the obtained product at 180°C in an air atmosphere for 8h, and calcine at 600°C in an air atmosphere for 6h to obtain the finished catalyst, recorded as catalyst 3.

[0042] Example 4

[0043] 10kg Fe(NO 3 ) 3 9H 2 O, 11g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to prepare 50 liters of solution, and 12 kg of 25% ammonia water was added to deionized water to prepare 40 liters of solution. The iron-copper mixed solution was added to the ammonia solution for precipitation, the precipitation temperature was controlled to 90 ° C, the precipitation time was 20 min, and the end point pH was controlled at 6.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 104 g of potassium carbonate, 178 g of boric acid, 460 g of potassium silicate solution with a silicon dioxide content of 30%, and 74.9 g of potassium metavanadate were fully dissolved in 1.0 kg of deionized water to prepare a K element precursor aqueous solution. 153 g of Ba(NO 3 ) 2 Fully dissolve in 1.0 kg of deionized water to prepare a Ba auxiliary aqueous solution. Add the K element precursor aqueous solution and the Ba auxiliary aqueous solution to the filter cake for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 70°C, and the slurrying time to 50 min. After the slurrying is completed, the catalyst precursor slurry is obtained. Control the inlet temperature at 290°C and the outlet hot air temperature at 120°C for spray drying, collect the spray drying product, dry the obtained product at 200°C in an air atmosphere for 6 hours, and calcine at 600°C in an air atmosphere for 8 hours to obtain a finished catalyst, recorded as Catalyst 4.

[0044] Example 5

[0045] 10kg Fe(NO 3 ) 3 9H 2 O, 263g Cu(NO 3 ) 2·3H 2 O, 26g Ba(NO 3 ) 2 Dissolve in deionized water to make 50 liters of solution, add 3.5kg of sodium carbonate, 1.73kg of sodium silicate solution with a silica mass concentration of 20%, and 258.1g of sodium metavanadate into deionized water to make 40 liters of solution. Add a mixed solution containing iron, copper, and barium to an ammonia silicon solution for precipitation, control the precipitation temperature to 10°C, the precipitation time to 90min, and the endpoint pH to 7.0. After the precipitation reaction is completed, filter and wash the precipitated slurry several times to obtain a catalyst precursor filter cake. Dissolve 12g of potassium carbonate and 59g of boric acid in 1.5kg of deionized water to prepare an aqueous solution of K element precursor. Add the aqueous solution of K element precursor to the catalyst precursor filter cake for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 10°C, the slurrying time to 60min, and after the slurrying is completed, obtain a catalyst precursor slurry. The inlet temperature was controlled at 260°C and the outlet hot air temperature was controlled at 110°C for spray drying, and the spray drying product was collected. The obtained product was dried at 220°C in an air atmosphere for 4 h, and calcined at 550°C in an air atmosphere for 10 h to obtain a finished catalyst, which was recorded as Catalyst 5.

[0046] Example 6

[0047] 10kg Fe(NO 3 ) 3 9H 2 O, 11g Cu(NO 3 ) 2 ·3H 2 O, 79g Ba(NO 3 ) 2Dissolve in deionized water to make 50 liters of solution, add 4.5kg of ammonium carbonate, 120g of sodium silicate solution with a silica mass concentration of 30% and 374.6g of potassium metavanadate to deionized water to make 40 liters of solution. Add the mixed solution containing iron, copper and barium to the ammonia silicon solution for precipitation, control the precipitation temperature to 30°C, the precipitation time to 30min, and the endpoint pH to 8.5. After the precipitation reaction is completed, filter and wash the precipitated slurry several times to obtain a catalyst precursor filter cake. Dissolve 195g of potassium carbonate and 79g of boric acid in 1.5kg of deionized water to prepare a K element precursor aqueous solution. Add the K element precursor aqueous solution and 1.04Kg of silica sol solution with a silica mass concentration of 30% to the catalyst precursor filter cake for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 25°C, the slurrying time to 20min, and after the slurrying is completed, obtain a catalyst precursor slurry. The inlet temperature was controlled at 230°C and the outlet hot air temperature was controlled at 105°C for spray drying. The spray drying product was collected and dried at 250°C in an air atmosphere for 3 h. The product was calcined at 400°C in an air atmosphere for 12 h to obtain a finished catalyst, which was recorded as Catalyst 6.

[0048] Example 7

[0049] 10kg Fe(NO 3 ) 3 9H 2 O, 263g Cu(NO 3 ) 2 ·3H 2O is dissolved in deionized water to prepare 50 liters of solution, and 8kg of 25% ammonia water and 690g of potassium silicate solution with a silica mass concentration of 20% are added to deionized water to prepare 40 liters of solution. A mixed solution containing iron and copper is added to the ammonia silicon solution for precipitation, the precipitation temperature is controlled to 50°C, the precipitation time is 60min, and the end point pH is controlled at 5.0. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 66g Ba(NO3)2 is fully dissolved in 0.5kg deionized water to prepare a Ba auxiliary agent aqueous solution. 195g potassium carbonate and 71g boric acid are fully dissolved in 1.0kg deionized water to prepare a K element precursor aqueous solution. 208.4g potassium metavanadate is fully dissolved in 0.5kg deionized water to prepare a V auxiliary agent precursor aqueous solution. The Ba auxiliary agent aqueous solution, K element precursor aqueous solution, and V auxiliary agent precursor aqueous solution were sequentially added to the catalyst precursor filter cake for slurrying, and the mass concentration of the slurry was controlled to be 15%, the slurrying temperature was 30°C, and the slurrying time was 30 minutes. After the slurrying was completed, the catalyst precursor slurry was obtained. The inlet temperature was controlled at 200°C and the outlet hot air temperature was controlled at 105°C for spray drying, and the spray drying product was collected. The obtained product was dried at 280°C in an air atmosphere for 2 hours, and calcined at 500°C in an air atmosphere for 8 hours to obtain a finished catalyst, which was recorded as catalyst 7.

[0050] Example 8

[0051] 10kg Fe(NO 3 ) 3 9H 2 O, 11g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to make 50 liters of solution, 9 kg of 25% ammonia water, 2.76 kg of sodium silicate solution with a silica mass concentration of 20%, and 337.1 g of potassium metavanadate were added to deionized water to make 40 liters of solution. The ammonia silicon solution was added to the mixed solution containing iron and copper for precipitation, the precipitation temperature was controlled to 70 ° C, the precipitation time was 40 min, and the end point pH was controlled at 6.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 137 g Ba(NO 3 ) 2Fully dissolve in 0.5 kg of deionized water to prepare a Ba auxiliary agent aqueous solution. Fully dissolve 12 g of potassium carbonate and 79 g of boric acid in 1.0 kg of deionized water to prepare a K element precursor aqueous solution. Add the Ba auxiliary agent aqueous solution and the K element precursor aqueous solution to the catalyst precursor filter cake in sequence for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 50°C, and the slurrying time to 40 min to obtain a catalyst precursor slurry. Control the inlet temperature at 180°C and the outlet hot air temperature at 100°C for spray drying, collect the spray drying product, dry the obtained product at 300°C in an air atmosphere for 1 h, and calcine at 550°C in an air atmosphere for 8 h to obtain a finished catalyst, recorded as Catalyst 8.

[0052] Example 9

[0053] 10kg Fe(NO 3 ) 3 9H 2 O, 137g Cu(NO 3 ) 2 ·3H 2 O, 875g Mg(NO 3 ) 2 6H 2 O and 158g boric acid are dissolved in deionized water to prepare 50 liters of solution, and 3kg sodium carbonate and 1.73kg sodium silicate solution with a silica mass concentration of 20% are added to deionized water to prepare 40 liters of precipitant solution. The mixed solution containing iron, copper and magnesium and the precipitant solution are precipitated together, the precipitation temperature is 30°C, the precipitation time is 80min, and the pH is controlled at 7.0. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 42g potassium nitrate is fully dissolved in 0.5kg deionized water to prepare a K element precursor aqueous solution. 149.8g potassium metavanadate is fully dissolved in 1.5kg deionized water to prepare a V auxiliary agent precursor aqueous solution. The K element precursor aqueous solution and the V auxiliary agent precursor aqueous solution are added to the catalyst precursor filter cake in sequence for slurrying, and the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 25°C, and the slurrying time is 50min to obtain a catalyst precursor slurry. The inlet temperature was controlled at 380°C and the outlet hot air temperature was controlled at 220°C for spray drying, and the spray drying product was collected. The obtained product was dried at 120°C in an air atmosphere for 12 h, and calcined at 600°C in an air atmosphere for 10 h to obtain a finished catalyst, which was recorded as Catalyst 9.

[0054] Example 10

[0055] 10kg Fe(NO 3 ) 3 9H 2O, 11g Cu(NO 3 ) 2 ·3H 2 O, 510 g Mg(NO 3 ) 2 6H 2 O and 79g boric acid are dissolved in deionized water to prepare 50 liters of solution, 4.5kg ammonium carbonate, 460g sodium silicate solution with a silica mass concentration of 30% and 292.2g potassium metavanadate are added to deionized water to prepare 40 liters of solution. The ammonia silicon solution is added to a mixed solution containing iron, copper and magnesium for precipitation, the precipitation temperature is controlled to 50°C, the precipitation time is 50min, and the endpoint pH is controlled to 8.5. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 18g potassium nitrate is fully dissolved in 1.0kg deionized water to prepare a K element precursor aqueous solution. The K element precursor aqueous solution is added to the catalyst precursor filter cake for slurrying, the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 30°C, the slurrying time is 60min, and after the slurrying is completed, a catalyst precursor slurry is obtained. The inlet temperature was controlled at 350°C and the outlet hot air temperature was controlled at 150°C for spray drying, and the spray drying product was collected. The obtained product was dried at 150°C in an air atmosphere for 10 h and calcined at 400°C in an air atmosphere for 9 h to obtain a finished catalyst, which was recorded as catalyst 10.

[0056] Embodiment 11

[0057] 10kg Fe(NO 3 ) 3 9H 2 O, 263g Cu(NO 3 ) 2 ·3H 2 O and 174g boric acid were dissolved in deionized water to prepare 50 liters of solution, and 8kg of 25% ammonia water and 33.1g of sodium metavanadate were added to deionized water to prepare 40 liters of solution. The ammonia solution was added to the mixed solution containing iron and copper for precipitation. The precipitation temperature was controlled to 90°C, the precipitation time was 20min, and the end point pH was controlled to 5.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 1167g Mg(NO 3 ) 2 6H 2O is fully dissolved in 0.5 kg of deionized water to prepare a Mg auxiliary agent aqueous solution. 286 g of potassium nitrate is fully dissolved in 0.5 kg of deionized water to prepare a K element precursor aqueous solution. The Mg auxiliary agent aqueous solution, the K element precursor aqueous solution and 1.84 kg of silica sol solution with a silica mass concentration of 30% are sequentially added to the catalyst precursor filter cake for slurrying. The mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 70°C, and the slurrying time is 20 min. After the slurrying is completed, the catalyst precursor slurry is obtained. The inlet temperature is controlled at 320°C and the outlet hot air temperature is controlled at 130°C for spray drying. The spray drying product is collected, and the obtained product is dried at 180°C in an air atmosphere for 8 hours, and calcined at 600°C in an air atmosphere for 4 hours to obtain a finished catalyst, which is recorded as catalyst 11.

[0058] Example 12

[0059] 10kg Fe(NO 3 ) 3 9H 2 O, 137g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to make 50 liters of solution, 9 kg of 25% ammonia water, 630 g of potassium silicate solution with a silica mass concentration of 30%, 63 g of boric acid and 374.6 g of potassium metavanadate were added to deionized water to make 40 liters of solution. The mixed solution containing iron and copper was precipitated together with the ammonia silicon solution at a precipitation temperature of 90 ° C, a precipitation time of 20 min, and a pH of 6.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 204 g of Ca(NO 3 ) 2 ·4H 2 O is fully dissolved in 1.0 kg of deionized water to prepare a Ca additive aqueous solution. The Ca additive aqueous solution and 530 g of potassium silicate solution with a silica mass concentration of 30% are sequentially added to the catalyst precursor filter cake for slurrying. The mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 70°C, and the slurrying time is 30 min. After the slurrying is completed, the catalyst precursor slurry is obtained. The inlet temperature is controlled at 290°C and the outlet hot air temperature is controlled at 120°C for spray drying. The spray drying product is collected, and the obtained product is dried at 200°C in an air atmosphere for 6 hours, and calcined at 600°C in an air atmosphere for 4 hours to obtain a finished catalyst, which is recorded as catalyst 12.

[0060] Example 13

[0061] 10kg Fe(NO 3 ) 3 9H 2O, 137g Cu(NO 3 ) 2 ·3H 2 O and 611 g Ca(NO 3 ) 2 ·4H 2 O is dissolved in deionized water to prepare 50 liters of solution, 3kg of sodium carbonate, 750g of silica sol solution with a silica mass concentration of 25%, 142g of boric acid and 109.2g of sodium metavanadate are added to deionized water to prepare 40 liters of solution. The ammonia silicon solution is added to the mixed solution containing iron, copper and calcium for precipitation, the precipitation temperature is controlled to 70°C, the precipitation time is 30min, and the end point pH is controlled to 7.0. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 630g of potassium silicate solution with a silica mass concentration of 25% is fully dissolved in 1.0kg of deionized water to prepare a K element precursor aqueous solution. The K element precursor aqueous solution is added to the catalyst precursor filter cake for slurrying, the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 50°C, and the slurrying time is 40min. After the slurrying is completed, a catalyst precursor slurry is obtained. The inlet temperature was controlled at 260°C and the outlet hot air temperature was controlled at 110°C for spray drying, and the spray drying product was collected. The obtained product was dried at 220°C in an air atmosphere for 4 hours and calcined at 450°C in an air atmosphere for 6 hours to obtain a finished catalyst, which was recorded as catalyst 13.

[0062] Embodiment 14

[0063] 10kg Fe(NO 3 ) 3 9H 2 O, 26g Cu(NO 3 ) 2 ·3H 2 O and 310 g Ca(NO 3 ) 2 ·4H 2O is dissolved in deionized water to prepare 50 liters of solution, and 4.5 kg of ammonium carbonate, 71 g of boric acid and 236 g of potassium metavanadate are added to deionized water to prepare 40 liters of solution. The mixed solution containing iron, copper and calcium is precipitated with the ammonia solution, the precipitation temperature is 30 ° C, the precipitation time is 70 min, and the pH is controlled at 8.5. After the precipitation reaction is completed, the precipitated slurry is filtered and washed several times to obtain a catalyst precursor filter cake. 580 g of potassium silicate solution with a silica mass concentration of 25% is fully dissolved in 0.5 kg of deionized water to prepare a K element precursor aqueous solution. The K element precursor aqueous solution and 1.08 kg of silica sol solution with a silica mass concentration of 25% are added to the catalyst precursor filter cake in sequence for slurrying, and the mass concentration of the slurry is controlled to be 15%, the slurrying temperature is 25 ° C, and the slurrying time is 50 min. After the slurrying is completed, a catalyst precursor slurry is obtained. The inlet temperature was controlled at 230°C and the outlet hot air temperature was controlled at 105°C for spray drying. The spray drying product was collected and dried at 250°C in an air atmosphere for 3 h and calcined at 550°C in an air atmosphere for 6 h to obtain a finished catalyst, which was recorded as catalyst 14.

[0064] Embodiment 15

[0065] 10kg Fe(NO 3 ) 3 9H 2 O, 68g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to make 50 liters of solution, 8 kg of 25% ammonia water, 770 g of sodium silicate solution with a silicon dioxide mass concentration of 25%, 142 g of boric acid and 172 g of sodium metavanadate were added to deionized water to make 40 liters of solution. The iron-copper mixed solution was precipitated with the ammonia-silicon solution at a precipitation temperature of 50 ° C, a precipitation time of 40 min, and a pH of 5.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 197 g Sr(NO 3 ) 2Fully dissolve in 1.0 kg of deionized water to prepare an Sr additive aqueous solution. Fully dissolve 107 g of potassium nitrate in 0.5 kg of deionized water to prepare a K element precursor aqueous solution. Add the Sr additive aqueous solution and the K element precursor aqueous solution to the catalyst precursor filter cake in sequence for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 30°C, and the slurrying time to 60 min. After the slurrying is completed, a catalyst precursor slurry is obtained. Control the inlet temperature at 200°C and the outlet hot air temperature at 100°C for spray drying, collect the spray drying product, dry the obtained product at 280°C in an air atmosphere for 2 hours, and calcine at 550°C in an air atmosphere for 4 hours to obtain a finished catalyst, recorded as catalyst 15.

[0066] Example 16

[0067] 10kg Fe(NO 3 ) 3 9H 2 O, 184g Cu(NO 3 ) 2 ·3H 2 O was dissolved in deionized water to make 50 liters of solution, 9 kg of 25% ammonia water, 550 g of sodium silicate solution with a silica mass concentration of 25%, 103 g of boric acid and 337.1 g of potassium metavanadate were added to deionized water to make 40 liters of solution. The iron-copper mixed solution was precipitated with the ammonia-silicon solution at a precipitation temperature of 10°C, a precipitation time of 90 min, and a pH of 6.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 117 g Sr(NO 3 ) 2 Fully dissolve in 0.5kg deionized water to prepare Sr auxiliary agent aqueous solution. Fully dissolve 214g potassium nitrate in 0.5kg deionized water to prepare K element precursor aqueous solution. Add Sr auxiliary agent aqueous solution, K element precursor aqueous solution and 550g silica sol solution with a silica mass concentration of 25% to the catalyst precursor filter cake in sequence for slurrying. Control the mass concentration of the slurry to 15%, the slurrying temperature to 10°C, and the slurrying time to 60min. After the slurrying is completed, add the catalyst precursor slurry. Control the inlet temperature at 180°C and the outlet hot air temperature at 100°C for spray drying, collect the spray drying product, dry the obtained product at 300°C in an air atmosphere for 1h, and calcine at 600°C in an air atmosphere for 2h to obtain the finished catalyst, recorded as catalyst 16.

[0068] Embodiment 17

[0069] 10kg Fe(NO 3 ) 3 9H2 O, 263g Cu(NO 3 ) 2 ·3H2O was dissolved in deionized water to make 50 liters of solution. 9kg of 25% ammonia water, 690g of potassium silicate solution with a silicon dioxide mass concentration of 20%, and 208.4g of sodium metavanadate were added to deionized water to make 40 liters of solution. The mixed solution containing iron and copper was precipitated together with the ammonia silicon solution. The precipitation temperature was 10°C, the precipitation time was 90min, and the pH was controlled at 6.0. After the precipitation reaction was completed, the precipitated slurry was filtered and washed several times to obtain a catalyst precursor filter cake. 100g Sr(NO 3 ) 2 Fully dissolve in 0.5 kg of deionized water to prepare an Sr additive aqueous solution. Fully dissolve 195 g of potassium carbonate and 79 g of boric acid in 0.5 kg of deionized water to prepare an aqueous solution of a K element precursor. Add the Sr additive aqueous solution and the K element precursor aqueous solution to the catalyst precursor filter cake in sequence for slurrying, control the mass concentration of the slurry to 15%, the slurrying temperature to 10°C, and the slurrying time to 60 min. After the slurrying is completed, a catalyst precursor slurry is obtained. Control the inlet temperature at 180°C and the outlet hot air temperature at 100°C for spray drying, collect the spray-dried product, dry the obtained product at 300°C in an air atmosphere for 1 h, and calcine at 600°C in an air atmosphere for 2 h to obtain a finished catalyst, recorded as catalyst 17.

[0070] Comparative Example 1

[0071] The method was carried out according to Example 1, except that Ba(NO 3 ) 2 . Recorded as contrast agent 1.

[0072] Comparative Example 2

[0073] The same method was carried out as in Example 2, except that no boric acid was added. This was recorded as Comparative Agent 2.

[0074] Comparative Example 3

[0075] The method was carried out according to Example 3, except that no boric acid and Ba(NO 3 ) 2 . Recorded as contrast agent 3.

[0076] Comparative Example 4

[0077] The same method was carried out as in Example 4, except that potassium metavanadate was not added. This method was recorded as Comparative Agent 4.

[0078] Comparative Example 5

[0079] The method was carried out according to Example 5, except that sodium metavanadate and Ba(NO 3 ) 2 . Recorded as contrast agent 5.

[0080] Comparative Example 6

[0081] The same method was carried out as in Example 6, except that potassium metavanadate and boric acid were not added. This was recorded as Comparative Agent 6.

[0082] Comparative Example 7

[0083] The method was carried out according to Example 9, except that Mg(NO 3 ) 2 6H 2 O. Recorded as contrast medium 9.

[0084] Comparative Example 8

[0085] The same method as in Example 12 was used except that no Ca(NO 3 ) 2 ·4H 2 O. Recorded as contrast agent 12.

[0086] Comparative Example 9

[0087] The same method was used as in Example 15, except that no Sr auxiliary aqueous solution was added. This was recorded as Comparative Agent 15.

[0088] II. Performance Test

[0089] After the catalyst and the comparison agent were prepared, the performance test was carried out by the following method:

[0090] Test equipment: 1L stirred tank;

[0091] Test conditions: 10g of catalyst was mixed with 300mL of liquid paraffin and placed in a 1L stirred tank device. After reduction activation, the reaction conditions were switched to conduct the reaction. The corresponding reduction activation and Fischer-Tropsch synthesis reaction process conditions are as follows:

[0092] (1) Reduction activation: use H 2 The synthesis gas with a CO / CO ratio of 20:1 was reduced by heating (4 h at 30-200 °C, 10 h at 200-265 °C, and 24 h at 265 °C), and the space velocity of the synthesis gas was 8000 h -1 , the reduction gauge pressure is 3.0MPa.

[0093] (2) Fischer-Tropsch synthesis: After the reduction is completed, the synthesis gas H 2The / CO ratio was adjusted to 3:1 and stabilized for a period of time until the gas phase composition in the reaction tail gas basically did not change with time, which was recorded as the reaction 0 point.

[0094] (3) Data calculation: The molar number of CO in the feed was measured at the feed port of the stirred tank, and the molar number of CO and CO in the discharge was measured at the discharge port. 2 , CH 4 The molar number of C5+ and olefins (C5+) is used to calculate the CO conversion rate % [X(CO)], CO 2 Selectivity % [S(CO 2 )], CH 4 Selectivity % [S(CH 4 )], C5+ selectivity [S(C5+)] and olefin selectivity (C5+):

[0095] CO conversion rate % = [(CO moles in feed - CO moles in discharge) / CO moles in feed] × 100%;

[0096] CO 2 Selectivity % = [CO in the discharge 2 mole number / (mole number of CO in feed - mole number of CO in discharge)] × 100%;

[0097] CH 4 Selectivity % = [CH 4 mole number / (mole number of CO in feed × CO conversion rate % × (1-CO 2 Selectivity %))]×100%.

[0098] C5+ selectivity % = [C5+ moles in the output / (CO moles in the feed × CO conversion % × (1-CO 2 Selectivity %))]×100%.

[0099] Olefin selectivity (C5+)% = [mol number of olefins (C5+) in the output / (mol number of CO in the feed × CO conversion rate %) × (1-CO 2 Selectivity %))]×100%.

[0100] The deactivation rate of the catalyst refers to the rate at which the catalyst activity (carbon monoxide conversion rate) decreases from the reaction plateau to the end of the reaction, and the unit is % / h.

[0101] The composition, physical structure and reaction performance results of the catalyst are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] The composition, physical structure and reaction performance results of the contrast agent are shown in Table 2 below.

[0105] Table 2

[0106]

[0107] It is easy to understand that the above embodiments are only examples for clear explanation and do not mean that the present invention is limited thereto. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the present invention.

Claims

1. A Fischer-Tropsch synthesis iron-based catalyst comprising Fe, Cu, K, SiO 2 and M, in, M is a ternary composite additive, which is composed of V element, B element and alkaline earth metal element, and the alkaline earth metal element is selected from at least one of Ba element, Mg element, Ca element and Sr element; Among them, calculated by mass ratio, when Fe element:V element=100:1~less than 5.5, Fe element:B element=100:1.5~2.5, Fe element:alkaline earth metal element=100:5.5~10; when Fe element:V element=100:5.5~10, Fe element:B element=100:0.5~less than 1.5, Fe element:alkaline earth metal element=100:1~less than 5.

5.

2. The Fischer-Tropsch synthesis iron-based catalyst according to claim 1, It is characterized in that By mass ratio, Fe element:Cu element:K element:SiO 2 :M=100:0.2~5:0.5~8:10~42:6.5~18.

3. The method for preparing the Fischer-Tropsch synthesis iron-based catalyst according to claim 1 or 2, wherein The following steps are involved: S1: forming a mixed aqueous solution of a water-soluble salt of an Fe element and a water-soluble salt of a Cu element, preparing a precipitant solution, and adding 0 to 100 wt % of a silicon source to the precipitant solution; S2: contacting the mixed aqueous solution with the precipitant solution to perform a precipitation reaction, and separating the obtained precipitation product after the reaction is completed; S3: mixing the precipitation product with the K element precursor aqueous solution and the remaining silicon source to form a mixed slurry and performing slurry treatment to obtain a catalyst precursor slurry; as well as S4: drying and calcining the catalyst precursor slurry; The method of adding the V element includes: adding a water-soluble salt of the V element to the mixed aqueous solution and / or the precipitant solution in step S1; or adding a water-soluble salt of the V element to the K element precursor aqueous solution and / or the mixed slurry in step S3; The method of adding the B element includes: adding a boron source to the mixed aqueous solution and / or the precipitant solution in step S1; or adding a boron source to the precursor aqueous solution and / or the mixed slurry of the K element in step S3; Among them, the method of adding alkaline earth metal elements includes: adding water-soluble salts or hydroxides of alkaline earth metal elements to the mixed aqueous solution of step S1; or preparing water-soluble salts or hydroxides of alkaline earth metal elements into an aqueous solution, and then adding them to the K element precursor aqueous solution and / or mixed slurry of step S3.

4. The preparation method according to claim 3, It is characterized in that The water-soluble salt of the V element is one or more of the metavanadates; and / or the water-soluble salt of the alkaline earth metal element is a nitrate or a hydrate thereof; and / or the boron source is one or more of boric acid, metaboric acid, boric oxide, and a water-soluble borate; preferably, the water-soluble borate is potassium borate and / or sodium borate.

5. The preparation method according to claim 3 or 4, It is characterized in that The water-soluble salt of the Fe element is a nitrate, a hydrochloride or a hydrate of Fe; the water-soluble salt of the Cu element is a nitrate, a hydrochloride or a hydrate of Cu; preferably, the concentration of Fe in the mixed aqueous solution is 5 to 100 g / L; and / or The precipitant is selected from one or more of sodium carbonate, ammonia water, ammonium carbonate, sodium hydroxide, potassium hydroxide, and potassium carbonate; preferably, the concentration of the precipitant is 50-150 g / L.

6. The preparation method according to any one of claims 3 to 5, It is characterized in that The silicon source is selected from one or more of potassium silicate solution, sodium silicate solution and silica sol solution, wherein SiO 2 The concentration is 10 to 50 wt%; and / or The K element precursor is one or more of potassium nitrate, potassium carbonate, potassium bicarbonate, potassium chloride, and potassium silicate.

7. The preparation method according to any one of claims 3 to 6, It is characterized in that In the step S2, the precipitation temperature of the precipitation reaction is 5 to 95° C., the precipitation time is 5 to 100 min, and the pH value is controlled at 5 to 10 during the precipitation process.

8. The preparation method according to any one of claims 3 to 7, It is characterized in that In the step S3, the slurrying temperature of the slurrying treatment is 10-80° C., the slurrying time is 10-80 min, and the concentration of the slurry is controlled to be 5-40 wt % during the slurrying treatment.

9. The preparation method according to any one of claims 3 to 8, It is characterized in that In the step S4, the drying includes the following process: firstly, the catalyst precursor slurry is spray-dried, and the obtained powder is dried in an air atmosphere at 110-300° C. for 1-12 hours; Preferably, the hot air inlet temperature of the spray drying is 180-400°C, and the exhaust air outlet temperature is 100-220°C.

10. The preparation method according to any one of claims 3 to 9, It is characterized in that In the step S4, the calcination temperature is 400-600° C. and the calcination time is 1-15 hours.

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