A process for the hydrogenation of olefins to alkanes

Abstract

This invention discloses a method for the hydrogenation of olefins to alkanes, belonging to the field of petrochemical technology. The invention uses olefins and hydrogen as raw materials, and a single-atom catalyst Pd / Zn / M / Al2O3 as a catalyst to carry out a hydrogenation reaction to obtain alkanes. The single-atom catalyst Pd / Zn / M / Al2O3 consists of an Al2O3 support, modified components supported on the Al2O3 support, and an active component. The modified component includes Zn and / or Zn oxides and M and / or M oxides; the active component includes Pd and / or Pd oxides. This invention achieves excellent hydrogenation performance under low temperature, low pressure, and low hydrogen-to-oil ratio conditions, significantly improving conversion rate and selectivity, and helping to reduce energy consumption and operating costs of the reaction unit, thus having practical industrial significance.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to a method for producing alkanes by hydrogenating olefins. Background Technology

[0002] Due to environmental requirements and policies, the GB22030-2017 standard stipulates that the mass fraction of artificially added oxygenated compounds other than ethanol cannot exceed 0.5%. In 2020, the country fully promoted ethanol gasoline, and MTBE (methyl tert-butyl ether) will no longer be allowed as an additive in gasoline, requiring a significant amount of C4 resources to be re-planned and utilized. Indirect alkylation refers to the process of C4 olefins dimerizing to form isooctene, followed by hydrogenation of isooctene to obtain isooctane. The advantages of indirect alkylation technology are its flexibility, low requirements for raw materials, and direct modification of MTBE units. The isooctene product obtained from the C4 olefin dimerization process during indirect alkylation is itself a high-octane gasoline component, with a RON value of 105 and a MON value of 95. When the requirements for gasoline olefin content are not strict, it can be directly added to gasoline to increase its octane number. However, with the tightening of gasoline standards in my country, the country has begun to restrict the olefin content in gasoline, necessitating further hydrogenation of isooctene to produce isooctane.

[0003] Isooctane is a petroleum additive with a high octane rating, low vapor pressure, and is free of sulfur, oxygen, aromatics, and olefins. Adding isooctane not only reduces the content of sulfur, olefins, and aromatics in gasoline, but also promotes complete combustion, effectively reducing exhaust pollution. Furthermore, due to its low vapor pressure, isooctane can reduce the fugitive emissions of volatile organic compounds during gasoline use and storage.

[0004] The conditions for the hydrogenation of isooctene are related to the catalyst used. Generally, when using precious metal catalysts such as platinum, palladium, and ruthenium, the reaction can be carried out under mild conditions of 80-200℃, hydrogen partial pressure of 1-2MPa, and hydrogen-to-oil ratio of 300-500:1. The hydrogen can pass through once without recycling, resulting in lower equipment investment and operating costs, but the catalyst is more expensive. On the other hand, when using non-precious metal catalysts such as Ranney nickel, amorphous nickel, and supported nickel catalysts, the reaction generally needs to be carried out under harsh conditions of 200-350℃, hydrogen partial pressure of 2-4MPa, and hydrogen-to-oil ratio of 500-1000:1. The hydrogen needs to be recycled, the catalyst is cheaper, but the equipment investment is larger, and there are high requirements for the sulfur content of the raw materials. Summary of the Invention

[0005] To address the shortcomings of existing isooctene hydrogenation technologies, the present invention aims to provide a method for olefin hydrogenation to alkanes. This method is characterized by the use of a single-atom alloy catalyst with Al2O3 as a support, which exhibits excellent low-temperature activity. Under conditions of low temperature, low pressure, and low hydrogen-to-oil ratio, it achieves superior hydrogenation performance, significantly improving conversion rate and selectivity. This method also helps reduce energy consumption and operating costs of the reaction unit, and has practical industrial significance.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for the hydrogenation of olefins to alkanes, comprising the following steps: using olefins and hydrogen as raw materials, and using a single-atom catalyst Pd / Zn / M / Al2O3 as a catalyst, a hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Zn / M / Al2O3 consists of an Al2O3 support and modified components and an active component supported on the Al2O3 support; the modified components include Zn and / or Zn oxides and M and / or M oxides; the active component includes Pd and / or Pd oxides; ... is used as a raw material, and the hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Zn / M / Al2O3 is used as a raw material, and the hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Zn / M / Al2O3 is used as a raw material, and the hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Zn / M / Al2O3 is used as a raw material, and the hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Zn / M / Al2O3 is used as a raw material, and the hydrogenation reaction is carried out to obtain alkanes; wherein the single-atom catalyst Pd / Z The total mass of the atomic catalyst Pd / Zn / M / Al2O3 is calculated based on the following: Al2O3 content is 60wt%-99.9wt%, Pd and / or Pd oxide content is 0.005wt%-1wt%, Zn and / or Zn oxide content is 0.05wt%-30wt%, and M and / or M oxide content is 0.1wt%-10wt%. M is one or more of Cu, Ni, Ga, In, Y, La, Ce, Sm, Pr, and Nb.

[0008] In some preferred embodiments of the present invention, the hydrogenation reaction is carried out in a reactor, and the reactor reaction conditions are as follows: inlet temperature of 60℃-180℃, preferably 80℃-150℃; pressure of 1.0MPa-6.0MPa, preferably 2.0MPa-5.0MPa; molar ratio of hydrogen to olefin of 100:1-1000:1, preferably 200-500:1; and volume hourly space velocity of 0.5 h⁻¹. -1 -10.0h -1 1.0h is preferred -1 -5.0h -1 .

[0009] In some preferred embodiments of the present invention, the reactor is a fixed-bed reactor, a moving-bed reactor, a fluidized-bed reactor, or a batch reactor, preferably a fixed-bed reactor.

[0010] In some preferred embodiments of the present invention, the olefin is R1, R2, R3, and R4 are selected from H, alkyl, alkenyl, alkoxy, alkynyl, cycloalkyl, cycloalkenyl, or cycloalkynyl, and are preferably isooctene.

[0011] In some preferred embodiments of the present invention, the single-atom catalyst Pd / Zn / M / Al2O3 is prepared by first loading M and / or an oxide of M onto the Al2O3 support, then loading Zn and / or an oxide of Zn, and finally loading Pd and / or an oxide of Pd.

[0012] In some preferred embodiments of the present invention, the preparation method of the above-mentioned single-atom catalyst Pd / Zn / M / Al2O3 includes the following steps:

[0013] 1) An Al2O3 support was impregnated with a soluble salt impregnation solution containing 0.1-20 wt% dispersant a and M element, and the product obtained after impregnation was dried and calcined to obtain a surface-modified M / Al2O3 composite oxide.

[0014] 2) The surface-modified M / Al2O3 composite oxide is impregnated with a soluble salt impregnation solution containing 0.1-20wt% dispersant a and Zn element, and the product obtained after impregnation is dried and calcined to obtain the surface-modified Zn / M / Al2O3 composite oxide.

[0015] 3) The surface-modified Zn / M / Al2O3 composite oxide is impregnated with a soluble salt impregnation solution containing 0.1-20wt% dispersant b and Pd element, the pH value of the impregnation solution is controlled at 3-9, and the product obtained after impregnation is dried and calcined to obtain the catalyst precursor.

[0016] 4) The obtained catalyst precursor was reduced to obtain the single-atom catalyst Pd / Zn / M / Al2O3.

[0017] In some preferred embodiments of the present invention, in step 1), the Al2O3 is one or more mixed crystal forms of Al2O3, including γ crystal form, δ crystal form, θ crystal form, and α crystal form.

[0018] In some preferred embodiments of the present invention, in step 1), the Al2O3 support is pretreated. The pretreatment process is as follows: the Al2O3 support is soaked in a 0.5-10wt% alkaline ethanol solution, filtered, dried, and calcined at 400℃-1400℃ for 1-12 hours.

[0019] In some preferred embodiments of the present invention, the alkali is sodium hydroxide or potassium hydroxide, the solid-liquid mass ratio of the soaking is 1:(5-20), the soaking time is 3-18h, the drying temperature is 80-120℃, and the drying time is 5-20h.

[0020] In some preferred embodiments of the present invention, the Al2O3 carrier is spherical, cylindrical, annular, strip-shaped, clover-shaped, or tetraclover-shaped.

[0021] In some preferred embodiments of the present invention, in steps 1) and 2), the dispersant a is one or more of sodium dodecyl sulfate, diethylene glycol, sodium dodecylbenzene sulfonate, sodium pyrophosphate, sodium polyacrylate, sodium dodecyl sulfonate, and Tween series.

[0022] In some preferred embodiments of the present invention, in step 1), the soluble salt of element M is a nitrate, sulfate, or chloride of element M.

[0023] In some preferred embodiments of the present invention, in step 2), the soluble salt of Zn is a nitrate, sulfate, or chloride of Zn.

[0024] In some preferred embodiments of the present invention, in step 3), the dispersant b is one or more of cysteine, dodecyl dimethylamine oxide, hexadecyl dimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, PEG, PVP, PVB; the reagent used to control the pH value of the impregnation solution is one or more of ethylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, glutathione, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, ammonia, diethylamine, triethylamine; the soluble salt of Pd element is the nitrate, sulfate, or chloride of Pd element; the solution used to dissolve the soluble salt of Pd element during the preparation of the impregnation solution is an acidic solution, including nitric acid solution, sulfuric acid solution, and hydrochloric acid solution.

[0025] In some preferred embodiments of the present invention, in steps 1), 2), and 3), the calcination temperature is 200°C-1300°C and the time is 1h-12h.

[0026] In some preferred embodiments of the present invention, in steps 1), 2), and 3), the drying temperature is 60°C-150°C and the time is 1h-24h.

[0027] In some preferred embodiments of the present invention, the reduction temperature in step 4) is 80℃-600℃, the time is 1h-12h, and the hydrogen flow rate is 10ml / min-100ml / min.

[0028] The advantages of this invention over the prior art are as follows:

[0029] 1. In the single-atom alloy catalyst structure of this invention, there is a coordination interaction between the Pd and Zn metals, and the separation is relatively uniform. The catalytic performance can be affected by adjusting the type of metal M and the relative content of the metals. The single-atom alloy catalyst exhibits superior catalytic performance compared to single-metal catalysts in the reaction, which stems from the bifunctionality of the two metals or the synergistic effect between the two metals—including geometric and electronic effects. In single-atom alloy catalysts, the geometric effect refers to the change in spatial arrangement caused by the difference in chemical composition. The two metals have a certain spatial isolation, and the number of multi-metal central sites (bridge sites and triple sites, etc.) is reduced, thereby changing the adsorption configuration and reaction pathway of the substrate. The electronic effect refers to the change in electronic properties caused by the coordination of two metals with different electronegativity, thereby changing the adsorption strength of the substrate and thus changing the catalytic performance. Geometric and electronic effects are interdependent and mutually influential. In this invention, the Pd-Zn bimetallic structure is transformed from a face-centered cubic structure with disordered atomic arrangement to a body-centered cubic structure with highly ordered atomic arrangement, achieving effective separation of Pd sites within the unit cell. Furthermore, the transformation of the crystal structure is accompanied by a shortening of the Pd-Zn bond length, leading to an increase in the overlap of d orbitals and causing the d-band center to shift away from the Fermi level. Therefore, the Pd-centered single-atom alloy catalyst with a body-centered cubic structure has a simple structure and forms a stable geometric configuration. This reduces the adsorption of C=C bonds while enhancing the dissociation of H2 molecules, resulting in high selectivity in selective hydrogenation reactions. Meanwhile, the selectivity trend of the Pd / Zn / M / Al2O3 single-atom alloy catalyst shows that the high selectivity is due to the high electron density of Pd in ​​Pd / Zn / M / Al2O3, which can repel nucleophilic C=C bonds and accelerate C=C bond desorption. Additionally, the surface Zn and M atoms act as magnets for Pd... 0 / Pd 2+ The regulation of atomic ratio and the content of oxidation state of Pd active component may be key factors determining hydrogenation catalytic performance. At the same time, hydrogen atoms are more likely to overflow on the surface of metal Zn and M than on the surface of gold, thus making the Pd / Zn / M / Al2O3 single-atom alloy catalyst more active.

[0030] 2. The alumina-supported palladium single-atom catalyst of the present invention utilizes a dispersant as a ligand and some simple control operations to obtain a highly dispersed palladium single-atom catalyst. This catalyst exhibits high activity and selectivity in the hydrogenation reaction of unsaturated hydrocarbons; moreover, the addition of a dispersant makes this highly dispersed palladium exhibit better stability in the reaction; finally, the highly dispersed palladium catalyst also shows better atom utilization and reduced catalyst preparation cost in the reaction. This is because the interaction between the precursor species Pd-Zn and M and the support affects the adsorption of the metal complex on the support. These interactions include ion exchange or electrostatic adsorption. The exchange between the ligand and the surface hydroxyl group is a complex process, but electrostatic interaction is dominant. In acidic solutions, the Al2O3 support is positively charged due to polarization, and the palladium complex ions are also positively charged. If the acidity is very strong, the electrostatic repulsion results in a weak adsorption force between the support and the palladium metal ion complex, so the active component is easily detached from the support. As the pH value increases, the interaction between the support and the palladium metal ion complex also increases. In alkaline solution, the Al2O3 support becomes negatively charged due to polarization, while the palladium complex ions are positively charged. Due to electrostatic effects, the mutual attraction between the support and the palladium ion complex is strong, reaching its maximum at a certain pH value. The active components are evenly distributed on the surface of the support, thus forming a single-atom catalyst, which is then reduced to form a single-atom alloy catalyst. Attached Figure Description

[0031] To more clearly illustrate the embodiments of the present invention, the accompanying drawings involved in the embodiments will be briefly described below.

[0032] Figure 1 Transmission electron microscopy (TEM) image of the Pd / Zn / M / Al2O3 single-atom catalyst. Detailed Implementation

[0033] The following provides a detailed description of the embodiments of the present invention. These embodiments are implemented based on the technical solution of the present invention and provide detailed implementation methods and processes. However, the scope of protection of the present invention is not limited to the following embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions.

[0034] Example 1

[0035] Catalyst preparation:

[0036] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 1.224 g of Cu(NO3)2·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Cu / Al2O3 composite oxide.

[0037] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Cu / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Cu / Al2O3 composite oxide.

[0038] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Cu / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Cu / Al2O3 catalyst precursor.

[0039] 4) Reduction treatment: The obtained Pd / Zn / Cu / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Cu / Al2O3 single-atom catalyst.

[0040] Isooctene hydrogenation reaction:

[0041] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0042] Example 2

[0043] Catalyst preparation:

[0044] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.609 g of Ga(NO3)3·9H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Ga / Al2O3 composite oxide.

[0045] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ga / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ga / Al2O3 composite oxide.

[0046] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ga / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Ga / Al2O3 catalyst precursor.

[0047] 4) Reduction treatment: The obtained Pd / Zn / Ga / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ga / Al2O3 single-atom catalyst.

[0048] Isooctene hydrogenation reaction:

[0049] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0050] Example 3

[0051] Catalyst preparation:

[0052] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1379 g of In(NO3)3·5H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified In / Al2O3 composite oxide.

[0053] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add In / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / In / Al2O3 composite oxide.

[0054] 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / In / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / In / Al2O3 catalyst precursor.

[0055] 4) Reduction treatment: The obtained Pd / Zn / In / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / In / Al2O3 single-atom catalyst.

[0056] Isooctene hydrogenation reaction:

[0057] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0058] Example 4

[0059] Catalyst preparation:

[0060] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.2268 g of Y(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Y / Al2O3 composite oxide.

[0061] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Y / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Y / Al2O3 composite oxide.

[0062] 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Y / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Y / Al2O3 catalyst precursor.

[0063] 4) Reduction treatment: The obtained Pd / Zn / Y / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Y / Al2O3 single-atom catalyst.

[0064] Isooctene hydrogenation reaction:

[0065] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0066] Example 5

[0067] Catalyst preparation:

[0068] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1641 g of La(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified La / Al2O3 composite oxide.

[0069] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add La / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / La / Al2O3 composite oxide.

[0070] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / La / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / La / Al2O3 catalyst precursor.

[0071] 4) Reduction treatment: The obtained Pd / Zn / La / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / La / Al2O3 single-atom catalyst.

[0072] Isooctene hydrogenation reaction:

[0073] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0074] Example 6

[0075] Catalyst preparation:

[0076] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1631 g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Ce / Al2O3 composite oxide.

[0077] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide.

[0078] 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ce / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor.

[0079] 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

[0080] Isooctene hydrogenation reaction:

[0081] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0082] Example 7

[0083] Catalyst preparation:

[0084] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.16 g of Nd(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Nd / Al2O3 composite oxide.

[0085] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Nd / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Nd / Al2O3 composite oxide.

[0086] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Nd / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Nd / Al2O3 catalyst precursor.

[0087] 4) Reduction treatment: The obtained Pd / Zn / Nd / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Nd / Al2O3 single-atom catalyst.

[0088] Isooctene hydrogenation reaction:

[0089] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0090] Example 8

[0091] Catalyst preparation:

[0092] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1555 g of Sm(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Sm / Al2O3 composite oxide.

[0093] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Nd / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Sm / Al2O3 composite oxide.

[0094] 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Sm / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 600℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Sm / Al2O3 catalyst precursor.

[0095] 4) Reduction treatment: The obtained Pd / Zn / Sm / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Sm / Al2O3 single-atom catalyst.

[0096] Isooctene hydrogenation reaction:

[0097] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0098] Example 9

[0099] The reduction treatment temperature was 100℃, and other conditions were the same as in Example 5.

[0100] Example 10

[0101] The fixed-bed reactor operates under the same conditions as in Example 6: inlet temperature of 120°C.

[0102] Example 11

[0103] Catalyst preparation: 1) The M / Al2O3 composite oxide was calcined in a muffle furnace at 1000℃ for 5h, with other conditions the same as in Example 8.

[0104] Example 12

[0105] The results after 500 hours of reaction are shown in Table 1. Other conditions were the same as in Example 2.

[0106] Example 13

[0107] Catalyst precursor: The pH of the solution was adjusted to 8.6 with ammonia water, and other conditions were the same as in Example 7.

[0108] Example 14

[0109] Catalyst precursor: Weigh 0.0189 g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 6.2% cysteine ​​and 8.5% PEG (nitric acid solution), and other conditions are the same as in Example 7.

[0110] Example 15

[0111] Catalyst precursor: Weigh 0.0189 g of Pd(NO3)2·2H2O and dissolve it in a 12.5% ​​3-aminopropyltrimethoxysilane solution. Adjust the pH of the solution to 6.7 with ammonia water. Other conditions are the same as in Example 7.

[0112] Comparative Example 1

[0113] Catalyst preparation:

[0114] 1) Weigh 5.0 g of Al2O3 support; then weigh 0.1641 g of La(NO3)3·6H2O, 0.2395 g of Zn(NO3)2·6H2O and 0.0189 g of Pd(NO3)2·2H2O and dissolve them in deionized water to prepare a solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 500℃ for 5 h. After cooling, take out the solid particles to obtain the Pd / Zn / La / Al2O3 catalyst precursor.

[0115] 2) Reduction treatment: The obtained Pd / Zn / La / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain the Pd / Zn / La / Al2O3 catalyst.

[0116] Isooctene hydrogenation reaction:

[0117] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0118] Comparative Example 2

[0119] Catalyst preparation:

[0120] 1) Weigh 5.0g of Al2O3 support; weigh 0.2395g of Zn(NO3)2·6H2O and 0.0189g of Pd(NO3)2·2H2O and dissolve them in deionized water to prepare a solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Al2O3 catalyst precursor.

[0121] 2) Reduction treatment: The obtained Pd / Zn / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain the Pd / Zn / Al2O3 catalyst.

[0122] Isooctene hydrogenation reaction:

[0123] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0124] Comparative Example 3

[0125] Catalyst preparation:

[0126] 1) M / Al2O3 composite oxide: Weigh 5.0g of Al2O3 support; weigh 0.2395g of Zn(NO3)2·6H2O and dissolve it in deionized water to prepare a solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Zn / Al2O3 composite oxide.

[0127] 2) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in deionized water to prepare a solution. Add the surface-modified Zn / Al2O3 composite oxide into the solution to allow the solution to be absorbed. Then, transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Al2O3 catalyst precursor.

[0128] 3) Reduction treatment: The obtained Pd / Zn / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Al2O3 single-atom catalyst.

[0129] Isooctene hydrogenation reaction:

[0130] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0131] Comparative Example 4

[0132] Catalyst preparation:

[0133] 1) Weigh 5.0g of Al2O3 support; then weigh 0.0126g of Pd(NO3)2·2H2O and dissolve it in deionized water to prepare a solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Al2O3 catalyst precursor.

[0134] 2) Reduction treatment: The obtained Pd / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain the Pd / Al2O3 catalyst.

[0135] Isooctene hydrogenation reaction:

[0136] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0137] Comparative Example 5

[0138] Catalyst preparation:

[0139] 1) Weigh 5.0g of Al2O3 support; then weigh 0.2182g of Zn(NO3)2·6H2O and dissolve it in deionized water to prepare a solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Zn / Al2O3 catalyst precursor.

[0140] 2) Reduction treatment: The obtained Zn / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain the Zn / Al2O3 catalyst.

[0141] Isooctene hydrogenation reaction:

[0142] Fixed-bed reactor operating conditions: inlet temperature 120℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0143] Comparative Example 6

[0144] Catalyst preparation:

[0145] 1) M / Al2O3 composite oxide: Weigh 5.0g of Al2O3 support; then weigh 0.2395g of Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Zn / Al2O3 composite oxide.

[0146] 2) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Al2O3 composite oxide to the solution, adjust the pH of the solution to 8.6 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Al2O3 catalyst precursor.

[0147] 3) Reduction treatment: The obtained Pd / Zn / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Al2O3 single-atom catalyst.

[0148] Isooctene hydrogenation reaction:

[0149] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0150] Comparative Example 7

[0151] Catalyst preparation:

[0152] 1) M / Al2O3 composite oxide: Weigh 5.0g of Al2O3 support; then weigh 0.1631g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 600℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Ce / Al2O3 composite oxide.

[0153] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide.

[0154] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ce / Al2O3 composite oxide to the solution, adjust the pH of the solution to 8.6 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor.

[0155] 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

[0156] Isooctene hydrogenation reaction:

[0157] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0158] Comparative Example 8

[0159] Catalyst preparation:

[0160] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1631 g of Ce(NO3)3·6H2O and dissolve it in deionized water. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Ce / Al2O3 composite oxide.

[0161] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide.

[0162] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ce / Al2O3 composite oxide to the solution, adjust the pH of the solution to 8.6 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor.

[0163] 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

[0164] Isooctene hydrogenation reaction:

[0165] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0166] Comparative Example 9

[0167] Catalyst preparation:

[0168] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1631 g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Ce / Al2O3 composite oxide.

[0169] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in deionized water. Add Ce / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide.

[0170] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ce / Al2O3 composite oxide to the solution, adjust the pH of the solution to 8.6 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor.

[0171] 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

[0172] Isooctene hydrogenation reaction:

[0173] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0174] Comparative Example 10

[0175] Catalyst preparation:

[0176] 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1631 g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain the surface-modified Ce / Al2O3 composite oxide.

[0177] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / Al2O3 composite oxide to the solution, adjust the pH of the solution to 13.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide.

[0178] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in deionized water. Add the surface-modified Zn / Ce / Al2O3 composite oxide into the solution to allow the solution to be absorbed. Then, transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor.

[0179] 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

[0180] Isooctene hydrogenation reaction:

[0181] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0182] Comparative Example 11

[0183] Catalyst preparation:

[0184] 1) M / Al2O3 composite oxide: Weigh 5.0g of SiO2 support; then weigh 0.1631g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 600℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Ce / SiO2 composite oxide.

[0185] 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / SiO2 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / SiO2 composite oxide.

[0186] 3) Catalyst precursor: Weigh 0.0189g of Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP (nitric acid solution). Add the surface-modified Zn / Ce / SiO2 composite oxide to the solution, adjust the pH of the solution to 8.6 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 400℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / SiO2 catalyst precursor.

[0187] 4) Reduction treatment: The obtained Pd / Zn / Ce / SiO2 catalyst precursor was treated at a temperature of 500℃ for 2 hours with a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / SiO2 single-atom catalyst.

[0188] Isooctene hydrogenation reaction:

[0189] Fixed-bed reactor operating conditions: inlet temperature 100℃, pressure 2.6MPa, hydrogen-to-oil ratio 200:1, volumetric hourly space velocity 3.0h⁻¹. -1 The results after 24 hours of reaction are shown in Table 1.

[0190] Table 1. Conversion and selectivity results of isooctene hydrogenation reactions in Examples 1-15 and Comparative Examples 1-11

[0191]

[0192]

[0193] This invention may have other embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of this invention.

Claims

1. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using Pd / Zn / Cu / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity (VHSV) 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 1.224 g of Cu(NO3)2·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Cu / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Cu / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Cu / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Cu / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Cu / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Cu / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Cu / Al2O3 single-atom catalyst.

2. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using Pd / Zn / Ga / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity (VHSV) 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.609 g of Ga(NO3)3·9H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Ga / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ga / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ga / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Ga / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Ga / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Ga / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ga / Al2O3 single-atom catalyst.

3. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using Pd / Zn / In / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1379 g of In(NO3)3·5H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified In / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add In / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / In / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / In / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / In / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / In / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / In / Al2O3 single-atom catalyst.

4. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using Pd / Zn / Y / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.2268 g of Y(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Y / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in a 10.0% sodium dodecyl sulfate solution. Add Y / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Zn / Y / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Y / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / Y / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Y / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Y / Al2O3 single-atom catalyst.

5. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using Pd / Zn / La / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity (VHSV) 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1641 g of La(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified La / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in a 10.0% sodium dodecyl sulfate solution. Add the La / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then, transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the surface-modified Zn / La / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / La / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain the Pd / Zn / La / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / La / Al2O3 catalyst precursor was reduced at a temperature of 500℃ or 100℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / La / Al2O3 single-atom catalyst.

6. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using a Pd / Zn / Ce / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature of 100℃ or 120℃, pressure of 2.6 MPa, hydrogen-to-oil ratio of 200:1, and volumetric hourly space velocity of 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1631 g of Ce(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Ce / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Ce / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Ce / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Ce / Al2O3 composite oxide to the solution. Adjust the pH of the solution to 5.2 with ethylenediamine, stir, and let it stand for 2 hours. Then, transfer it to an oven and dry it at 120℃ for 15 hours. Transfer it to a muffle furnace and calcine it at 400℃ for 4 hours. After cooling, take out the solid particles to obtain the Pd / Zn / Ce / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Ce / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Ce / Al2O3 single-atom catalyst.

7. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using a Pd / Zn / Nd / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity (VHSV) 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.16 g of Nd(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Nd / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Nd / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Nd / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Nd / Al2O3 composite oxide to the solution, adjust the pH of the solution to 5.2 with ethylenediamine, stir and let stand for 2h. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 4h. After cooling, take out the solid particles to obtain the Pd / Zn / Nd / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Nd / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Nd / Al2O3 single-atom catalyst.

8. A method for producing isooctane by hydrogenation of isooctene, characterized in that, Using a Pd / Zn / Sm / Al₂O₃ single-atom catalyst as the catalyst, the fixed-bed reactor was operated under the following conditions: inlet temperature 100℃, pressure 2.6 MPa, hydrogen-to-oil ratio 200:1, and volumetric hourly space velocity (VHSV) 3.0 h⁻¹. -1 ; The preparation of the catalyst includes the following steps: 1) M / Al2O3 composite oxide: Weigh 5.0 g of Al2O3 support that has been treated with 5% sodium hydroxide ethanol solution and calcined at 750℃ for 4 h; then weigh 0.1555 g of Sm(NO3)3·6H2O and dissolve it in 16.5% Tween-40 solution. Add the Al2O3 support to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15 h. Transfer it to a muffle furnace and calcine it at 600℃ or 1000℃ for 5 h. After cooling, take out the solid particles to obtain surface-modified Sm / Al2O3 composite oxide. 2) Zn / M / Al2O3 composite oxide: Weigh 0.2395g Zn(NO3)2·6H2O and dissolve it in 10.0% sodium dodecyl sulfate solution. Add Sm / Al2O3 composite oxide to the solution to allow the solution to be absorbed. Then transfer it to an oven and dry it at 120℃ for 15h. Transfer it to a muffle furnace and calcine it at 500℃ for 5h. After cooling, take out the solid particles to obtain surface-modified Zn / Sm / Al2O3 composite oxide. 3) Catalyst precursor: Weigh 0.0189g Pd(NO3)2·2H2O and dissolve it in a mixed solution of 4.3% glutathione and 7.7% PVP in nitric acid. Add the surface-modified Zn / Sm / Al2O3 composite oxide to the solution. Adjust the pH of the solution to 5.2 with ethylenediamine, stir, and let it stand for 2 hours. Then, transfer it to an oven and dry it at 120℃ for 15 hours. Transfer it to a muffle furnace and calcine it at 600℃ for 4 hours. After cooling, take out the solid particles to obtain the Pd / Zn / Sm / Al2O3 catalyst precursor. 4) Reduction treatment: The obtained Pd / Zn / Sm / Al2O3 catalyst precursor was reduced at a temperature of 500℃ for 2 hours and a hydrogen flow rate of 40 ml / min to obtain a Pd / Zn / Sm / Al2O3 single-atom catalyst.

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