A nickel-ruthenium-based solid superacid hydrogenation catalyst, a preparation method and application thereof

Abstract

A nickel-ruthenium-based solid superacid hydrogenation catalyst, its preparation method, and its application. The method includes: dissolving (NH4)2S2O8 in methanol, adding ZrO2 and continuing stirring and sonication, followed by stirring, filtering, drying the precipitate overnight, grinding the solid into powder after cooling, and then... o S2O8 was obtained by calcination at C for 3 h. 2‑ / ZrO2; Dissolve nickel and ruthenium salts in deionized water, sonicate, and then add S2O8. 2‑ / ZrO2, after further sonication, was reduced by adding NaBH4 solution, and the solution changed from light green to dark black; the mixture was filtered, vacuum dried, and ground to obtain the hydrogenation catalyst. This invention introduces a second metal Ru to the single-metal Ni-based solid superacid catalyst 10%Ni-S2O8. 2‑ A bimetallic Ni-Ru catalyst was prepared by modifying ZrO2. This catalyst exhibited higher catalytic activity in the catalytic hydrogenation of coal model compounds.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to a nickel-ruthenium-based hydrogenation catalyst, its preparation method, and its application. Background Technology

[0002] Due to the scarcity of petroleum resources and high dependence on imported oil, the search for alternative fuels has gradually become a research hotspot in the energy field. Because of its similar properties to natural crude oil, the utilization value of coal has received increasing attention from researchers. Coal is a byproduct of coal pyrolysis, and its composition includes a large proportion of aliphatic hydrocarbons, aromatics, and phenols, with monocyclic and bicyclic aromatics being the predominant components. Therefore, dearomatization has become a crucial step in coal hydrorefining processes. The basic process of aromatic hydrocarbon hydrogenation is as follows: under certain temperature and pressure, an addition reaction occurs with hydrogen. Depending on the catalyst type, aromatic hydrocarbon hydrogenation generally involves first hydrogen saturation, followed by the cracking of saturated cycloalkanes. Hydrogen saturation of aromatics and ring-opening reactions of cycloalkanes can also occur simultaneously. The cracking process of saturated cycloalkanes follows a carbon-ion mechanism, involving isomerization and ring-opening reactions. The hydrogenation of polycyclic aromatic hydrocarbons (PAHs) not only improves the yield and quality of light oils but is also crucial for extending catalyst lifespan; therefore, PAH hydrogenation has attracted considerable attention.

[0003] Lignite has an extremely complex structure. Direct application to hydrogenolysis would result in overly complex product compositions, hindering the analysis of catalytic reaction mechanisms and the optimization of process parameters. Lignite, with its lower degree of coalification compared to other coal types, retains many macromolecular characteristics of coal-forming plants, particularly the structural features of lignin. Analysis shows that the organic structure of this type of lignite is rich in aromatic CO bonds, primarily consisting of α-O-4, β-O-4, and 4-O-5 bond types. Their bond dissociation energies are 218, 289, and 314 kJ / mol, respectively, with the 4-O-5 bond exhibiting the highest bond energy among all CO bond types. Therefore, the selective cleavage of 4-O-5 CO bonds is a key technological step in the synthesis of high-value-added chemicals.

[0004] The most critical technology in coal hydrogenation is the preparation of highly efficient hydrogenation catalysts for the catalytic hydrogenation of aromatics in the feedstock. Traditional transition metal hydrogenation catalysts exhibit poor activity in aromatic hydrogenation, requiring stringent reaction conditions that are no longer sufficient for practical production needs. Therefore, to achieve the key to aromatic hydrogenation in coal, it is necessary to develop highly efficient and readily available hydrogenation catalysts. Nickel-based catalysts, due to their excellent catalytic hydrogenation performance, have significant application value in the field of heterogeneous catalysis. For heterogeneous catalytic reaction systems, in addition to the active metal, the catalyst support is also a key factor affecting the hydrogenolysis of lignite and its model compounds. Solid superacid catalysts possess both Lewis and Beta acids; they can act as catalysts themselves or as supports for metals to synthesize metal-acid bifunctional catalysts. By utilizing the synergistic effect between the metal sites and the acidic components, their catalytic performance can be significantly improved. Sulfuric acid is a common strong acid, and its synthesis in the form of sulfated metal oxide solid superacids poses certain risks. In contrast, ammonium persulfate is safer, and solid superacid catalysts synthesized using ammonium persulfate possess more Lewis and Beta acid sites, resulting in superior catalytic performance. Although it exhibits some catalytic efficiency in the depolymerization and conversion of lignite and its derivatives under mild conditions, its activity and stability still need further improvement. Therefore, developing Ni-based solid superacid catalysts with higher activity is particularly important. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method for preparing a highly selective and highly dispersed nickel-ruthenium-based solid superacid hydrogenation catalyst.

[0006] The second objective of this invention is to provide a highly efficient nickel-ruthenium-based solid superacid hydrogenation catalyst prepared by the above-described method.

[0007] The third objective of this invention is to provide the application of the above-mentioned high-efficiency nickel-ruthenium-based solid superacid hydrogenation catalyst in the catalytic hydrogenation of coal model compounds.

[0008] To achieve the above objectives, the present invention provides a method for preparing a nickel-ruthenium-based solid superacid catalyst, comprising the following steps:

[0009] S1. Dissolve (NH4)2S2O8 in methanol and stir until completely dissolved to obtain ammonium persulfate methanol solution; add ZrO2 to the solution, continue stirring and sonicating for 8-12 min, then stir for 7-9 h, filter, place the precipitate in a vacuum oven to dry overnight, and after the solid cools, grind it into powder, then at 550 °C o After being calcined at C for 3 h, S2O8 was finally obtained. 2- / ZrO2;

[0010] S2. Preparation of nickel-ruthenium-based hydrogenation catalyst by initial wet impregnation method: Weigh nickel salt and ruthenium salt and dissolve them in deionized water to obtain metal precursor solution, sonicate for 8-12 min, and then add S2O8. 2- After sonicating ZrO2 for 10-20 minutes, NaBH4 solution was added for reduction, and the solution changed from light green to dark black. The mixture was filtered, then vacuum dried and ground to obtain a nickel-ruthenium-based solid superacid hydrogenation catalyst.

[0011] Preferably, in step S2, the concentrations of nickel salt and ruthenium salt in the metal precursor solution are 1M and 0.1M, respectively; and the loadings of Ni and Ru in the nickel-ruthenium-based solid superacid hydrogenation catalyst are 10wt% and 0.5~1wt%, respectively.

[0012] Preferably, in step S2, the nickel salt is nickel nitrate; the ruthenium salt is ruthenium trichloride hydrate; and the concentration of the NaBH4 solution is 10 mg / mL.

[0013] Preferably, in step S1, the concentration of the ammonium persulfate methanol solution is 0.5 M; the mass ratio of (NH4)2S2O8 to ZrO2 is 3:25; and it is placed in a muffle furnace at 3... o The temperature was programmed to rise to 550 °C / min. o C and roast for 3 hours.

[0014] Preferably, in steps S1 and S2, after filtration, the precipitate is placed in a vacuum oven at 110°C. o C dry overnight.

[0015] To achieve the above-mentioned objectives, the present invention also provides a nickel-ruthenium-based solid superacid hydrogenation catalyst prepared by the preparation method described above.

[0016] To achieve the above-mentioned objectives, this invention also provides the application of the above-mentioned nickel-ruthenium-based solid superacid hydrogenation catalyst in the catalytic hydrogenation of coal model compounds.

[0017] Further, the specific application process is as follows: The coal model compound, nickel-ruthenium based solid superacid hydrogenation catalyst, and solvent are placed in a reactor, sealed, and hydrogen gas is introduced to purge residual air; subsequently, the reactor is pressurized to 0.1-2.0 MPa with hydrogen gas at room temperature, and then the reaction temperature is controlled at 110-150°C. o C, and react under stirring for 30-150 min; the mass ratio between the nickel-ruthenium-based solid superacid hydrogenation catalyst and the coal model compound is 1:(2-10); after the reaction is completed, the reaction system is naturally cooled to room temperature and the pressure is released, the reaction mixture is filtered to remove the catalyst, and the organic phase is obtained by gas chromatography-mass spectrometry and gas phase analysis.

[0018] Preferably, the reactor is pressurized to 1.0 MPa with hydrogen at room temperature, and then the reaction temperature is controlled at 140°C. o C, and reacted for 120 min under stirring, with the mass ratio of the nickel-ruthenium-based solid superacid hydrogenation catalyst to the coal model compound being 1:2.5; the mass-to-volume ratio of the coal model compound to the solvent being 5 mg:1 mL; and the stirring speed being 800 rpm.

[0019] Preferably, the coal model compound is one of diphenyl ether, benzyl ether, phenoxyethylbenzene, dibenzyl ether, 4-phenoxyphenol, and p-xylyl ether; the solvent is isopropanol or n-hexane.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] Given the advantages of bimetallic catalysts in catalytic performance, this invention introduces a second metal, Ru, to the 10%Ni-S2O8 monometallic Ni-based solid superacid catalyst. 2- Bimetallic Ni-Ru catalysts were prepared by modifying ZrO2. The strong interaction between Ni and Ru metals in the modified solid superacid catalyst promotes greater metal dispersion, smaller metal particle size, and stronger acidity, thereby facilitating milder hydrogenolysis conditions for lignin and its model compounds. Attached Figure Description

[0022] Figure 1 The N2 adsorption-desorption isotherms (a) and pore size distribution diagrams (b) of the catalysts prepared in Examples 1-3 and Comparative Examples 3-6 of this invention are shown.

[0023] Figure 2 These are the XRD patterns of the catalysts prepared in Examples 1-3 and Comparative Examples 3-6 of the present invention, respectively;

[0024] Figure 3 These are SEM images of the catalysts prepared in Example 1 and Comparative Examples 2-6 of this invention, respectively. (a) 10% Ni-S2O8 2 / ZrO2, (b)0.5%Ru-S2O8 2 / ZrO2, (c) 10%Ni-0.5%Ru-S2O8 2- / ZrO2, (d) 10%Ni-1%Fe-S2O8 2 / ZrO2, (e) 10%Ni-1%Ga-S2O8 2 / ZrO2, (f) 10%Ni-1%Co-S2O8 2 / ZrO2;

[0025] Figure 4These are TEM images of the catalysts prepared in Example 1 and Comparative Examples 2-3 of this invention, respectively. (a) 10% Ni-S2O8 2 / ZrO2, (b)0.5%Ru-S2O8 2 / ZrO2, (c) 10%Ni-0.5%Ru-S2O8 2- / ZrO2;

[0026] Figure 5 The average particle size diagrams of the catalysts prepared in Example 1 and Comparative Examples 2-3 of this invention are shown. (a) 10% Ni-S2O8 2 / ZrO2, (b)0.5%Ru-S2O8 2 / ZrO2, (c) 10%Ni-0.5%Ru-S2O8 2- / ZrO2;

[0027] Figure 6 The 10%Ni-0.5%Ru-S2O8 prepared in Example 1 of this invention 2- HRTEM and SAED images of the ZrO2 catalyst;

[0028] Figure 7 The 10%Ni-0.5%Ru-S2O8 prepared in Example 1 of this invention 2- HAADF-STEM image (j) and elemental distribution diagram (ei) of ZrO2 catalyst;

[0029] Figure 8 These are XPS images of the catalysts prepared in Example 1 and Comparative Examples 2-3 of this invention, respectively. (a) 10% Ni-S2O8 2 / ZrO2 Ni 2p 3 / 2 XPS spectra, (b) 10%Ni-0.5%Ru-S2O8 2- / ZrO2 Ni 2p 3 / 2 XPS spectra, (c) 0.5% Ru-S2O8 2 / ZrO2 of Ru 3d 5 / 2 XPS spectra, (d) 10%Ni-0.5%Ru-S2O8 2- / ZrO2 of Ru 3d 5 / 2 XPS diagrams;

[0030] Figure 9 These are the FT-IR spectra of the catalysts prepared in Example 1 and Comparative Examples 2-3 of this invention, respectively;

[0031] Figure 10 These are the NH3-TPD spectra of the catalysts prepared in Example 1 and Comparative Example 3 of this invention, respectively;

[0032] Figure 11 This is a schematic diagram showing the effect of different reaction conditions on the hydrogenation conversion of diphenyl ether. (a) shows the effect of temperature; (b) shows the effect of pressure; (c) shows the effect of reaction time; and (d) shows the effect of catalyst dosage. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] A nickel-ruthenium based solid superacid catalyst 10%Ni-0.5%-S2O8 2- The preparation method of / ZrO2 includes the following steps:

[0036] S1. Dissolve 0.12 g of (NH4)2S2O8 in methanol solution and stir until completely dissolved. Then add 1 g of ZrO2 to the solution and continue stirring and sonicating for 10 min. Then stir magnetically for 8 h, filter, and dry in a vacuum oven at 110 °C. o Dry at 3°C ​​overnight, and after the solid cools, grind it into powder and place it in a muffle furnace at 3°C. o The temperature was programmed to rise to 550 °C / min. o C was then calcined for 3 hours to finally obtain S2O8. 2- / ZrO2;

[0037] S2. Preparation of nickel-ruthenium-based hydrogenation catalyst by initial wet impregnation method: Weigh 0.2755 g of nickel nitrate and 0.0063 g of ruthenium trichloride hydrate and dissolve them in 15 mL of deionized water as metal precursors. Sonicate for 10 min, then add 0.5 g of S2O8. 2- After sonicating ZrO2 for 15 min, 50 mL of 10 mg / mL NaBH4 solution was added for reduction, and the solution changed from light green to dark black. The mixture was filtered and then dried in a vacuum oven at 110°C. o After drying at C overnight and grinding, a nickel-based solid superacid catalyst was obtained, labeled as 10%Ni-0.5%Ru-S2O8 based on the metal loading of Ni and Ru. 2- / ZrO2.

[0038] Example 2

[0039] A nickel-ruthenium-based solid superacid catalyst (10% Ni-0.1% Ru-S2O8) 2- The method for preparing ZrO2 differs from that in Example 1 in that in step S2, "0.2755g of nickel nitrate and 0.0013g of ruthenium trichloride hydrate are weighed and dissolved in 15 mL of deionized water as a metal precursor". All other steps are consistent with those in Example 1.

[0040] Example 3

[0041] A nickel-ruthenium based solid superacid catalyst 10%Ni-1%Ru-S2O8 2- The method for preparing ZrO2 differs from that in Example 1 in that in step S2, "0.2755g of nickel nitrate and 0.013g of ruthenium trichloride hydrate are weighed and dissolved in 15 mL of deionized water as a metal precursor". All other steps are consistent with those in Example 1.

[0042] Comparative Example 1

[0043] A type of S2O8 2- The method for preparing the / ZrO2 catalyst is consistent with step S1 in Example 1.

[0044] Comparative Example 2

[0045] A ruthenium-based solid acid catalyst 0.5% Ru-S2O8 2 The method for preparing / ZrO2 differs from that in Example 1 in that in step S2, "only 0.0063g of ruthenium trichloride hydrate is weighed and dissolved in 15 mL of deionized water as a metal precursor," while the other steps remain consistent with Example 1.

[0046] Comparative Example 3

[0047] A nickel-based solid acid catalyst 10% Ni-S2O8 2 The method for preparing / ZrO2 differs from that in Example 1 in that ruthenium trichloride hydrate is not added in step S2, while the other steps remain the same as in Example 1.

[0048] Comparative Example 4

[0049] A nickel-cobalt based solid acid catalyst 10%Ni-1%Co-S2O8 2 The method for preparing ZrO2 differs from that in Example 1 in that in step S2, "0.2755g of nickel nitrate and 0.0158g of cobalt nitrate are weighed and dissolved in 15 mL of deionized water as metal precursors". All other steps are consistent with those in Example 1.

[0050] Comparative Example 5

[0051] A nickel-gallium based solid acid catalyst 10%Ni-1%Ga-S2O8 2The method for preparing ZrO2 differs from that in Example 1 in that step S2 involves "weighing 0.2755g of nickel nitrate and 0.0099g of gallium nitrate and dissolving them in 15 mL of deionized water as metal precursors". All other steps remain the same as in Example 1.

[0052] Comparative Example 6

[0053] A nickel-iron based solid acid catalyst 10%Ni-1%Fe-S2O8 2 The method for preparing ZrO2 differs from that in Example 1 in that in step S2, "0.2755g of nickel nitrate and 0.0221g of ferric nitrate are weighed and dissolved in 15 mL of deionized water as metal precursors". All other steps are consistent with those in Example 1.

[0054] The catalysts obtained in Examples 1-3 and Comparative Examples 1-6 were characterized as follows, and the results are shown in Table 1 below.

[0055] Table 1 Physical structural properties of catalysts

[0056]

[0057] S BET Total specific surface area; S meso Mesoporous surface area; S micro : Micropore surface area; V t Total pore volume; V meso Mesopore volume; V micro : Micropore volume; D ave Average aperture

[0058] a The total specific surface area is calculated using the BET method.

[0059] b The total orifice volume was calculated at a relative pressure P / P0 = 0.99.

[0060] c The average aperture was calculated using the BJH method.

[0061] d. Difference subtraction calculation

[0062] Depend on Figure 1As shown in Figure a, the N2 adsorption-desorption isotherms of all catalysts exhibit similar characteristic curves, with their adsorption and desorption curves essentially overlapping. No obvious hysteresis was observed, indicating that the prepared catalyst samples are predominantly microporous with a low content of mesopores. The pore size distribution calculated by the BJH method is shown in Figure a. Figure 1 As shown in b, the pore sizes of all catalysts are mainly concentrated in the mesoporous range of 2-10 nm, indicating that the small amount of pores in the samples are predominantly mesoporous. Analysis of the data in Table 1 shows that both the pure solid superacid support and the catalysts after metal loading have relatively small total specific surface area and total pore volume. Furthermore, bimetallic loading did not significantly change the specific surface area of ​​the catalyst. Based on these results, it can be concluded that the pore structure of the catalyst has little impact on its hydrogenation performance. The XRD detection results of the samples prepared in Examples 1-3 and Comparative Examples 3-6 of this invention are shown in [Table 1]. Figure 2 In the case of 10%Ni-1%Co-S2O8 2- / ZrO2 and 10%Ni-1%Co-S2O8 2- With the ZrO2 catalyst, an effect of 2θ value of 28.2 can be observed. o 50.0 o The characteristic diffraction peaks representing ZrO2 gradually weakened at 44.5 nm, indicating a decrease in crystallinity. However, the characteristic diffraction peaks of ZrO2 prepared by introducing a second metal, Fe or Ru, or changing the loading of the second metal did not show significant changes. All samples showed peaks around 44.5 nm. o 51.8 o and 76.3 o The characteristic peak of Ni appears at 2θ, corresponding to the (111), (200), and (220) crystal planes of Ni, respectively. Due to the low loading of the second metal, its corresponding characteristic diffraction peak was not observed. This is because the interaction between the metals improves the dispersion of the metal particles, thereby making the bimetallic catalyst exhibit superior catalytic activity compared to the single-metal Ni-based catalyst.

[0063] SEM images of the samples prepared in Example 1 and Comparative Examples 2-6 of this invention are shown below. Figure 3 As shown, the Ni-based monometallic catalyst exhibits a honeycomb-like structure with numerous micropores and mesopores distributed on its surface. In contrast, the ruthenium-based monometallic catalyst displays an irregular blocky structure with a relatively smooth surface. The bimetallic catalysts prepared by introducing second metals Ru, Fe, Ga, and Co show similar morphologies without significant changes, all exhibiting a loose and porous structure, which greatly promotes the dispersion of metal particles.

[0064] To gain a deeper understanding of the microstructural characteristics of the catalyst, TEM characterization was performed in this invention. Figure 4 and Figure 5 The display shows 10% Ni-S2O8 2- / ZrO2 and 0.5%Ru-S2O8 2- TEM images of the ZrO2 catalyst show a uniform distribution with average particle sizes of 16.1 nm and 9.64 nm, respectively. When in 10% Ni-S2O8... 2- Introducing 0.5% Ru metal into ZrO2 reduced the average metal particle diameter of the catalyst to approximately 12.45 nm, indicating that the addition of Ru significantly reduced the size of the metal particles. The study suggests that the synergistic effect between Ni and Ru not only helps improve the dispersion of the metal components but also effectively inhibits metal agglomeration, resulting in a more uniform particle size distribution. The size and morphology of metal particles or clusters have a significant impact on the activity of metal catalysts. Reducing the size of metal particles or decreasing the degree of aggregation generally helps improve the catalytic performance of the catalyst. Figure 6 Medium 10%Ni-0.5%Ru-S2O8 2- HRTEM characterization results of the ZrO2 catalyst showed that the diffraction spots in the SAED and FFT patterns mainly originated from the lattice diffraction of Ru species. Calculations revealed that the interplanar spacings of two adjacent planes were 0.214 and 0.234 nm, respectively, which correspond to the Ru species. 0 The (002) and (100) crystal planes of the species correspond. Based on HAADF-STEM characterization results ( Figure 7 j), 10%Ni-0.5%Ru-S2O8 2- The metal nanoparticles in the ZrO2 catalyst exhibit a highly dispersed state on the support surface, with a narrow particle size distribution. Furthermore, elemental surface scan analysis further confirms this. Figure 7 The five elements (Ni, Ru, S, Zr, and O) were uniformly distributed on the catalyst surface. Studies have shown that the size distribution and dispersion state of the metal particles are key factors affecting the hydrogenation activity of the catalyst. Generally, smaller metal particle size and higher dispersion effectively increase the number of surface active sites, thereby improving the catalytic efficiency and allowing the catalyst to exhibit superior catalytic performance.

[0065] The valence and chemical states of the metal elements on the catalyst surface were analyzed using X-ray photoelectron spectroscopy (XPS). All binding energies were corrected relative to the C 1s peak (CC bond, 284.8 eV). Figure 8 The results show that in 10% Ni-S2O8 2- / ZrO2 Ni 2p 3 / 2 In the XPS spectrum, the peak at 852.1 eV corresponds to metallic Ni. 0 The other three peaks are attributed to Ni. 2+ Ni 3+And satellite peaks. The presence of these oxidized Ni peaks is due to the oxidation reaction that occurs after the sample is exposed to air and comes into contact with oxygen and moisture. However, in the bimetallic catalyst 10%Ni-0.5%Ru-S2O8 2- In ZrO2, Ni 2p 3 / 2 Ni in the spectrum 0 The binding energy rises to 852.7 eV. (This is in the case of a single metal 0.5% Ru-S₂O₈). 2- In the ZrO2 catalyst, Ru 3d 5 / 2 Metal Ru in the spectrum 0 The binding energy is 281.8 eV. In comparison, the bimetallic 10%Ni-0.5%Ru-S2O8... 2- / ZrO2 Ru 3d 5 / 2 The electron binding energy of the energy spectrum decreased by 0.6 eV. Additionally, due to Ru 3d... 3 / 2 The metal Ru of the orbit 0 The peak overlaps with the C 1s peak generated by surface carbon contamination, making it impossible to directly observe Ru. 0 In Ru 3d 3 / 2 Characteristic signals on the orbit. Analysis results indicate that the strong interaction between Ni and Ru induces electron transfer from Ni to Ru, thereby causing Ru... 0 The reduction in binding energy and Ni 0 Increase in binding energy.

[0066] Figure 9 The infrared spectra shown in the figures reveal that the three catalysts prepared in Example 1 and Comparative Examples 2-3 of this invention all exhibit similar infrared absorption peaks, indicating that they possess the same functional group structure. Compared to the single-metal Ni-based catalyst, the single-metal Ru-based catalyst shows similar infrared absorption peaks at 1278, 1635, and 3420 cm⁻¹. -1 The absorption peak at the point was significantly weakened. Furthermore, the bimetallic catalyst exhibited a similar trend after being loaded with a second metal, Ru, indicating that the introduction of Ru suppressed the stretching and bending vibrations of the OH bonds formed after water absorption, but did not significantly alter the basic structure of the catalyst.

[0067] The acidity of two samples prepared in Example 1 and Comparative Example 3 of this invention was systematically characterized using NH3-TPD technology. In this method, the NH3 desorption peak area can be used to quantify the acid content, while the desorption temperature reflects the acid strength. Specific results are as follows: Figure 10 As shown. Compared to single-metal Ni-based solid superacid catalysts, Ni-Ru bimetallic catalysts exhibit superior performance at 190°C. o The absence of an NH3 desorption peak at position C indicates the absence of a weak acid site; simultaneously, 718 o The smaller desorption peak at point C, representing the strong acid site, also disappeared. At 394...o A new desorption peak appeared at position C, indicating that the introduction of metallic Ru increased the number of medium-to-strong acid sites on the catalyst. Furthermore, the desorption peak representing strong acid sites increased from 604... o C shifted towards the low-temperature region.

[0068] Example 4: Hydrogenation application of the catalysts prepared in Examples 1-3

[0069] Taking the catalytic hydrogenation of diphenyl ether as an example: all catalytic reactions were carried out in a 100 mL stainless steel autoclave. In a typical experiment, the substrate diphenyl ether (100 mg), catalyst (40 mg), and isopropanol (20 mL) were placed into the reactor. After sealing, residual air was removed by purging with hydrogen three times. Subsequently, the reactor was pressurized with hydrogen to the desired pressure (1.0 MPa) at room temperature. The temperature was then raised to the required reaction temperature (140 °C). o The reaction mixture was stirred at 800 rpm for 120 min under vigorous stirring. After the experiment, the reaction system was allowed to cool naturally to room temperature and the pressure was released. The reaction mixture was filtered to remove the catalyst, and the obtained organic phase was analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography (GC).

[0070] Table 2 Catalytic performance of different catalysts for the hydrogenation of diphenyl ether

[0071]

[0072] The data in Table 2 above show that, without the addition of a catalyst or using only S2O8 2- In the blank experiment with ZrO2 support, the conversion efficiency of diphenyl ether in the reaction system was extremely low, close to zero. However, when loaded with metallic Ni, the conversion efficiency of 10% Ni-S2O8 was significantly improved. 2- / ZrO2 catalyst at 140 o Under the conditions of C, 1 MPa H2, and 2 h, a diphenyl ether conversion rate of 49.1% can be achieved, mainly producing benzene, cyclohexane, and cyclohexanol, indicating that the reaction pathway is dominated by hydrogenolysis. To improve the catalytic activity of the catalyst, second metals Co, Fe, Ga, and Ru were introduced for modification. It was observed that compared to the single-metal Ni-based catalyst, the Ni-Ru and Ni-Co bimetallic catalysts showed significantly improved catalytic performance under the same reaction conditions, with diphenyl ether conversion rates reaching 100% and 75.6%, respectively. Conversely, the Ni-Fe and Ni-Ga bimetallic catalysts inhibited the catalytic activity, reducing the diphenyl ether conversion rate to 39.6% and 40.8%, respectively. Based on this, the effect of different Ru addition amounts on the reaction was further investigated. The results showed that when 0.5% Ru metal was introduced, the 10%Ni-0.5%Ru-S2O8 reaction... 2-The ZrO2 catalyst exhibited excellent catalytic performance, achieving complete conversion of diphenyl ether with benzene, cyclohexane, and cyclohexanol remaining the main products, and the reaction pathway remained largely unchanged. Furthermore, the diphenyl ether conversion remained constant even when the Ru addition increased to 1%. (10% Ni-0.5% Ru-S2O8) 2- The high catalytic activity of ZrO2 can be attributed to the strong interaction between metals Ni and Ru, which reduces the metal particle size and improves the metal dispersion. This conclusion was verified by characterization methods such as XRD, SEM and TEM.

[0073] Based on the above research results, 10%Ni-0.5%Ru-S2O8 2- The ZrO2 catalyst exhibits high catalytic activity in the hydrogenolysis of CO bonds in diphenyl ether. However, the catalytic hydrogenolysis process is influenced by various factors; therefore, further in-depth research will be conducted to investigate the specific effects of different factors on the hydrogenolysis reaction.

[0074] Example 5: Effect of different solvents on the hydrogenation conversion of diphenyl ether

[0075] The process is the same as in Example 4, except that a different solvent is used.

[0076] Table 3 Hydrogenation of diphenyl ethers in different solvents

[0077]

[0078] Reaction conditions: 100 mg diphenyl ether, 40 mg catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL solvent, 140 o C, 2 h, 1 MPa H2.

[0079] In catalytic reactions, the choice of solvent often has a significant impact on the reaction process. To reveal the role of solvent in the conversion of diphenyl ether, a solvent of 10% Ni-0.5% Ru-S2O8 was used under a H2 atmosphere. 2-The effect of solvent on the hydrogenation conversion of diphenyl ether was investigated using a ZrO2 catalyst system. Specific experimental results are shown in Table 3. When methanol, ethanol, and tetrahydronaphthalene were used as solvents, the catalyst activity was low, and diphenyl ether was almost not converted. However, when n-hexane was used as the solvent, the conversion rate of diphenyl ether was significantly improved, reaching 32.5%, because H2 has higher solubility in alkane solvents than in alcohols. The catalyst exhibited very high catalytic activity when isopropanol was used as the solvent, achieving complete conversion of diphenyl ether under the same reaction conditions. Isopropanol plays a dual role in this reaction system: on the one hand, it acts as a reaction solvent; on the other hand, it undergoes a dehydrogenation process to generate acetone, releasing a large number of active hydrogen species. These in-situ generated active hydrogens, together with the hydrogen source provided by H2, form a synergistic effect, jointly participating in the hydrogenation conversion of diphenyl ether, thereby significantly improving the reaction efficiency.

[0080] Using isopropanol as a solvent, the effects of different reaction parameters (reaction temperature, hydrogen pressure, reaction time, and catalyst dosage) on 10% Ni-0.5% Ru-S2O8 were further investigated. 2- The influence of ZrO2 catalyst on the conversion of diphenyl ether.

[0081] Example 6: Effect of reaction temperature on the hydrogenation conversion of diphenyl ether

[0082] The process is the same as in Example 4, except that the reaction temperature is changed.

[0083] Reaction conditions: 100 mg diphenyl ether, 40 mg catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 2h, 1 MPa H2.

[0084] Example 7: Effect of hydrogen pressure on the hydrogenation conversion of diphenyl ether

[0085] The process is the same as in Example 4, except that the hydrogen pressure is changed.

[0086] Reaction conditions: 100 mg diphenyl ether, 40 mg catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 140 o C, 2 h.

[0087] Example 8: Effect of reaction time on the hydrogenation conversion of diphenyl ether

[0088] The process is the same as in Example 4, except that the reaction time is varied.

[0089] Reaction conditions: 100 mg diphenyl ether, 40 mg catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 140 o C, 1 MPa H2.

[0090] Example 9: Effect of catalyst dosage on the hydrogenation conversion of diphenyl ether

[0091] The process is the same as in Example 4, except that the amount of catalyst used is varied.

[0092] Reaction conditions: 100 mg diphenyl ether, catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 1 MPaH2, 140 o C, 2 h.

[0093] Figure 11 The experimental data from a revealed the effect of different reaction temperatures on 10% Ni-0.5% Ru-S2O8 2- The influence of ZrO2 on the conversion of diphenyl ethers. In the lower temperature range (110-140℃)... o Within (C), the conversion rate of diphenyl ether shows a rapid upward trend with increasing temperature, reaching a peak at 140°C. o Complete conversion was achieved under reaction conditions C, with benzene, cyclohexane, and cyclohexanol as the main products, and their contents gradually increased with increasing temperature. Meanwhile, the yield of cyclohexanol was consistently higher than that of cyclohexane, indicating that phenol is more readily subjected to aromatic ring hydrogenation than benzene. In addition, small amounts of the monocyclic hydrogenation product CPE and the bicyclic hydrogenation product OCE were also detected. When the temperature reached 150°C... o At temperature C, the conversion rate of diphenyl ether remained constant, but the yield of cyclohexane increased due to the hydrogenation of some benzene. Throughout the reaction, the yield of CPE showed a trend of first increasing and then decreasing. To avoid excessive hydrogenation of the product at high temperatures, the optimal reaction temperature for the conversion of diphenyl ether was determined to be 140°C. o C.

[0094] Figure 11 b. The effect of H2 pressure parameters on 10% Ni-0.5% Ru-S2O8 was investigated. 2- The mechanism of diphenyl ether conversion on ZrO2 catalyst. Experimental data show that lower H2 pressure (0.1 MPa) limits the hydrocracking capacity of the reaction system, resulting in lower diphenyl ether conversion and target product yield. At 140... oUnder reaction conditions of C and 2 h, as the H2 pressure increased from 0.1 MPa to 1 MPa, the conversion rate of diphenyl ether and the yield of the target product showed a gradual upward trend, achieving complete conversion at 1 MPa. When the H2 pressure was further increased, the conversion rate of the catalytic reaction remained stable. However, the yields of benzene and CPE showed a gradual decreasing and increasing trend, respectively, while the yield of cyclohexane showed a trend of first decreasing and then increasing. The results indicate that lower H2 pressure leads to lower catalyst activity and promotes the accumulation of intermediate products; while the reaction can achieve complete conversion, higher H2 pressure leads to excessive H2 consumption, resulting in resource waste. Therefore, this invention determines 1 MPa as the optimal hydrogen pressure condition for the reaction.

[0095] After determining the optimal reaction temperature (140°C) o Based on C) and hydrogen pressure (1 MPa) parameters, the effects of 10% Ni-0.5% Ru-S2O8 were further investigated. 2- The effect of reaction time on the distribution of conversion products during the ZrO2-catalyzed conversion of diphenyl ether was investigated to explore the internal mechanism and pathway of the reaction. Figure 11 The experimental results of c show that 10%Ni-0.5%Ru-S2O8 2- The ZrO2 catalyst exhibited excellent catalytic performance within a reaction time of 0.5–2.5 h. In the initial stage of the reaction (0.5 h), the conversion rate of diphenyl ether reached 89.9%, and the conversion rate continued to increase with increasing reaction time, reaching complete conversion after 1.5 h, and then remaining stable. Throughout the reaction, almost no bicyclic hydrogenation product OCE was observed. Product distribution analysis confirmed the main reaction pathway of diphenyl ether conversion: in the initial stage, diphenyl ether selectively hydrogenates to form the CPE intermediate, and subsequently, CPE mainly undergoes CO bond hydrogenolysis to generate monocyclic products such as benzene, cyclohexane, and cyclohexanol; only a small amount of CPE is further hydrogenated to convert to OCE. Considering all factors, 2 h was determined to be the optimal reaction time.

[0096] The amount of catalyst added has a significant impact on the efficiency of the diphenyl ether hydrogenolysis reaction. Figure 11 The experimental results of d show that when 10%Ni-0.5%Ru-S2O8 2-When the ZrO2 catalyst dosage varied from 10 to 50 mg, the conversion efficiency of diphenyl ether gradually increased, achieving complete conversion at a dosage of 40 mg and then remaining stable. At a catalyst dosage of 10 mg, the conversion rate of diphenyl ether was only 50.4%. This is mainly because a lower catalyst dosage reduces the number of available active metals, thus decreasing the number of active sites available for the reaction. This not only reduces the rate of active hydrogen generation but also decreases the number of adsorption sites for the reactants, thereby affecting the hydrogenolysis efficiency of the CO bond in diphenyl ether. With increasing catalyst dosage, the conversion rate of diphenyl ether remained stable, but some benzene in the product gradually hydrogenated to form cyclohexane. Based on these results, 40 mg was determined to be the optimal catalyst dosage for the reaction.

[0097] Example 10: 10% Ni-0.5% Ru-S2O8 2- Applications of ZrO2 in the catalytic hydrogenation of different substrates

[0098] The process is the same as in Example 4, except that a different substrate is used, namely a different coal model compound.

[0099] Table 4 10%Ni-0.5%Ru-S2O8 2- ZrO2-catalyzed hydrogenation of different substrates

[0100]

[0101] Reaction conditions: 100 mg of substrate (coal model compound), 40 mg of 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 1 MPa H2.

[0102] Based on 10%Ni-0.5%Ru-S2O8 2- The ZrO2 catalyst exhibited excellent catalytic activity in the hydrogenolysis of DPE, and its catalytic conversion performance for other lignite model compounds was further investigated. Through systematic study of the hydrogenolysis reactions of typical model compounds such as benzylphenyl ether and dibenzyl ether, the application potential of this catalyst in the conversion of coal-derived aromatic ethers was comprehensively evaluated. The conversion rates and product distributions of the relevant model compounds are shown in Table 4. Under their respective experimental conditions, 10% Ni-0.5% Ru-S2O8... 2-The ZrO2 catalyst exhibited excellent catalytic activity for various lignite model compounds (including DPE, BPE, PPE, p-xylyl ether, 4-phenoxyphenol, 4-4-dihydroxydiphenyl ether, and dibenzyl ether), achieving complete conversion of the reactants. Product analysis showed that the conversion of these aromatic ether compounds was mainly achieved through selective CO bond cleavage, and the products were almost entirely monocyclic aromatic compounds. The results indicate that under relatively mild reaction conditions, 10% Ni-0.5% Ru-S2O8... 2- The ZrO2 catalyst can precisely control the conversion process of all substrates, indicating that the catalyst has good catalytic activity and product selectivity.

Claims

1. A method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst, characterized in that, Includes the following steps: S1. Dissolve (NH4)2S2O8 in methanol and stir until completely dissolved to obtain ammonium persulfate methanol solution; add ZrO2 to the solution, continue stirring and sonicating for 8-12 min, then stir for 7-9 h, filter, place the precipitate in a vacuum oven to dry overnight, and after the solid cools, grind it into powder, then at 550 °C o After being calcined at C for 3 h, S2O8 was finally obtained. 2- / ZrO2; S2. Preparation of nickel-ruthenium-based hydrogenation catalyst by initial wet impregnation method: Weigh nickel salt and ruthenium salt and dissolve them in deionized water to obtain a metal precursor solution, wherein the concentrations of nickel salt and ruthenium salt in the metal precursor solution are 1 M and 0.1 M, respectively; sonicate for 8-12 min, and then add S2O8. 2- After sonicating ZrO2 for 10-20 min, a 10 mg / mL NaBH4 solution was added for reduction, and the solution changed from light green to dark black. The mixture was filtered, then vacuum dried and ground to obtain a nickel-ruthenium-based solid superacid hydrogenation catalyst. In the nickel-ruthenium-based solid superacid hydrogenation catalyst, the loadings of Ni and Ru were 10 wt% and 0.5-1 wt%, respectively.

2. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1, characterized in that, In step S2, the nickel salt is nickel nitrate; the ruthenium salt is ruthenium trichloride hydrate.

3. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1 or 2, characterized in that, In step S1, the concentration of the ammonium persulfate methanol solution is 0.5 M; the mass ratio of (NH4)2S2O8 to ZrO2 is 3:25; and it is placed in a muffle furnace at 3... o The temperature was programmed to rise to 550 °C / min. o C and roast for 3 hours.

4. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1 or 2, characterized in that, In steps S1 and S2, after filtration, the precipitate is placed in a vacuum oven at 110°C. o C-dry overnight.

5. A nickel-ruthenium-based solid superacid hydrogenation catalyst prepared by the preparation method according to any one of claims 1 to 4.

6. The application of the nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 5 in the catalytic hydrogenation of coal model compounds.

7. The application according to claim 6, characterized in that, The specific application process is as follows: The coal model compound, nickel-ruthenium based solid superacid hydrogenation catalyst, and solvent are placed in a reactor, sealed, and hydrogen gas is introduced to purge residual air. Subsequently, the reactor is pressurized to 0.1-2.0 MPa with hydrogen gas at room temperature, and then the reaction temperature is controlled at 110-150°C. o C, and react under stirring for 30-150 min; the mass ratio between the nickel-ruthenium-based solid superacid hydrogenation catalyst and the coal model compound is 1:(2-10); after the reaction is completed, the reaction system is naturally cooled to room temperature and the pressure is released, the reaction mixture is filtered to remove the catalyst, and the organic phase is obtained by gas chromatography-mass spectrometry and gas phase analysis.

8. The application according to claim 7, characterized in that, The reactor was pressurized to 1.0 MPa with hydrogen gas at room temperature, and then the reaction temperature was controlled at 140°C. o C, and reacted under stirring for 120 min, with the mass ratio of the nickel-ruthenium-based solid superacid hydrogenation catalyst to the coal model compound being 1:2.5; the mass-to-volume ratio of the coal model compound to the solvent being 5 mg:1 mL; and the stirring speed being 800 rpm.

9. The application according to claim 7, characterized in that, The coal model compound is one of diphenyl ether, benzyl ether, phenoxyethylbenzene, dibenzyl ether, 4-phenoxyphenol, and p-xylyl ether; the solvent is isopropanol or n-hexane.

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