Nickel-ruthenium-based solid superacid hydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention relates to a nickel-ruthenium-based solid superacid hydrogenation catalyst and a preparation method and application thereof, the method comprises the following steps: (NH4) 2S2O8 is dissolved in methanol, ZrO2 is added, stirring and ultrasonic treatment are continued, stirring and filtering are carried out, precipitate is dried overnight, solids are ground into powder after being cooled, and the powder is roasted at 550 DEG C for 3 h to obtain S2O8 < 2-> / ZrO2; the preparation method comprises the following steps: dissolving nickel salt and ruthenium salt in deionized water, performing ultrasonic treatment, adding S2O82- / ZrO2, continuing ultrasonic treatment, adding a NaBH4 solution for reduction, and changing the solution from light green to dark black; and filtering the mixture, drying in vacuum, and grinding to obtain the hydrogenation catalyst. According to the invention, a second metal Ru is introduced to modify a monometal Ni-based solid superacid catalyst 10% Ni-S2O8 < 2-> / ZrO2, and the bimetallic Ni-Ru catalyst is prepared. The catalyst has higher catalytic activity when applied to catalytic hydrogenation of coal model compounds.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and in particular to a nickel-ruthenium-based hydrogenation catalyst, a preparation method thereof, and applications thereof. Background Art

[0002] Due to the shortage of oil resources and high dependence on foreign oil imports, the search for alternative fuels has become a research hotspot in the energy sector. Due to its similar properties to natural crude oil, the utilization value of coal has attracted increasing attention from researchers. Coal is a byproduct of coal pyrolysis. Aliphatic hydrocarbons, aromatic hydrocarbons, and phenols account for a large proportion of its composition, with mono- and di-ring aromatics predominating. Therefore, dearomatization has become a key step in coal hydrorefining. The basic process of aromatic hydrogenation involves an addition reaction with hydrogen at a certain temperature and pressure. Depending on the catalyst type, aromatic hydrogenation generally begins with hydrogenation saturation, followed by cracking of saturated cycloalkanes. Hydrosaturation of aromatics and ring-opening of cycloalkanes can also occur simultaneously. The cracking of saturated cycloalkanes follows a carbon ion mechanism, with isomerization and ring-opening reactions occurring during the cracking process. Hydrogenation of polycyclic aromatic hydrocarbons not only increases the yield of light oil and improves oil quality, but is also crucial for extending the life of catalysts. Therefore, the hydrogenation of polycyclic aromatic hydrocarbons has attracted considerable attention.

[0003] Lignite has an extremely complex compositional structure. Directly applying it to hydrogenolysis would result in an overly complex product composition, hindering analysis of the catalytic reaction mechanism and optimizing process parameters. However, lignite has a lower degree of coalification and, compared to other coal types, retains many macromolecular features of coal-forming plants, particularly the structural characteristics of lignin. Analysis reveals 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. The 4-O-5 bond has the highest bond energy of all CO bonds. Therefore, 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 the coal hydrogenation process is the preparation of efficient hydrogenation catalysts to catalytically hydrogenate aromatics in the raw materials. Traditional transition metal hydrogenation catalysts have poor activity in the process of aromatic hydrogenation, and the required reaction conditions are harsh, which can no longer meet the needs of actual production. Therefore, the key to achieving the hydrogenation of aromatics in coal is to develop efficient and readily available hydrogenation catalysts. Nickel-based catalysts have important application value in the field of heterogeneous catalysis due to their excellent catalytic hydrogenation performance. For heterogeneous catalytic reaction systems, in addition to active metals, catalyst supports are also key factors affecting the hydrogenolysis of lignite and its model compounds. Solid superacid catalysts have both L acid and B acid. They can act as catalysts themselves for catalytic reactions, and can also be used as carriers to load metals to synthesize metal-acid bifunctional catalysts. The synergistic effect between metal sites and acidic components can significantly improve their catalytic performance. Sulfuric acid, a common strong acid, is somewhat hazardous in the synthesis of sulfated metal oxide-based solid superacids. Ammonium persulfate, by comparison, is safer, and solid superacid catalysts synthesized using ammonium persulfate possess more L- and B-acid sites, resulting in superior catalytic performance. While it exhibits some catalytic activity for the depolymerization of lignite and its derivatives under mild conditions, its activity and stability require further improvement. Therefore, the development of more active Ni-based solid superacid catalysts is crucial. Summary of the Invention

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

[0006] The second object of the present invention is to provide a high-efficiency nickel-ruthenium-based solid superacid hydrogenation catalyst prepared by the above preparation method.

[0007] A third object of the present invention is to provide the use 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 object, the present invention provides a method for preparing a nickel-ruthenium-based solid superacid catalyst, comprising 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 and continue stirring and ultrasonicating for 8-12 min, then stir for 7-9 h, filter and dry the precipitate in a vacuum oven overnight, grind into powder after the solid cools, and then o C and calcined for 3 h to obtain S2O8 2- / ZrO2; S2. Prepare nickel-ruthenium-based hydrogenation catalyst by incipient wetness impregnation method: weigh nickel salt and ruthenium salt and dissolve them in deionized water to obtain metal precursor solution, ultrasonicate for 8-12 min, and then add S2O82- / ZrO2, continue ultrasonication for 10-20 min, then add NaBH4 solution for reduction, and the solution changes from light green to dark black; the mixture is filtered, vacuum dried, and ground to obtain a nickel-ruthenium-based solid superacid hydrogenation catalyst.

[0009] Preferably, in step S2, the concentrations of nickel salt and ruthenium salt in the metal precursor solution are 1 M and 0.1 M, respectively; and the loading amounts of Ni and Ru in the nickel-ruthenium-based solid superacid hydrogenation catalyst are 10 wt% and 0.5-1 wt%, respectively.

[0010] 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.

[0011] Preferably, in step S1, the concentration of the ammonium persulfate methanol solution is 0.5M; the mass ratio of (NH4)2S2O8 to ZrO2 is 3:25; and the mixture is placed in a muffle furnace at 3 o The temperature was programmed to 550°C / min o C and calcined for 3 h.

[0012] Preferably, in steps S1 and S2, after filtering, the precipitate is placed in a vacuum oven at 110 o C and dried overnight.

[0013] To achieve the above-mentioned object of the invention, the present invention also provides a nickel-ruthenium-based solid superacid hydrogenation catalyst prepared by the above-mentioned preparation method.

[0014] To achieve the above-mentioned object of the invention, the present invention also provides the use of the above-mentioned nickel-ruthenium-based solid superacid hydrogenation catalyst in the catalytic hydrogenation of coal model compounds.

[0015] Furthermore, the specific application process is as follows: a coal model compound, a nickel-ruthenium-based solid superacid hydrogenation catalyst and a solvent are placed in a reactor, which is sealed and then hydrogen is introduced to remove the remaining air; the reactor is then pressurized to 0.1-2.0 MPa with hydrogen at room temperature, and the reaction temperature is then controlled to be 110-150 o C, and reacting for 30-150 minutes under stirring; the mass ratio between the nickel-ruthenium-based solid superacid hydrogenation catalyst and the coal model compound is 1:(2-10); after the reaction, 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 analyzed by gas chromatography-mass spectrometry and gas phase analysis.

[0016] Preferably, the reactor is pressurized to 1.0 MPa with hydrogen at room temperature, and then the reaction temperature is controlled to 140 oC, and reacted for 120 min under stirring, the mass ratio between the nickel-ruthenium-based solid superacid hydrogenation catalyst and the coal model compound was 1:2.5; the mass volume ratio between the coal model compound and the solvent was 5 mg:1 mL; and the stirring speed was 800 rpm.

[0017] Preferably, the coal model compound is one of diphenyl ether, benzyl phenyl ether, phenoxyethylbenzene, dibenzyl ether, 4-phenoxyphenol, and p-xylyl ether; and the solvent is isopropanol or n-hexane.

[0018] Compared with the prior art, the present invention has the following advantages: In view of the advantages of bimetallic catalysts in catalytic performance, the present invention introduces a second metal Ru into the single metal Ni-based solid superacid catalyst 10% Ni-S2O8 2- The strong interaction between the Ni and Ru metals in the modified solid superacid catalyst leads to a more dispersed metal, smaller metal particle size, and stronger acidity, thus promoting milder hydrogenolysis conditions for lignin and its model compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1. The N2 adsorption-desorption isotherms (a) and pore size distribution diagrams (b) of the catalysts prepared in Examples 1-3 of the present invention and Comparative Examples 3-6, respectively; Figure 2 are XRD patterns of the catalysts prepared in Examples 1-3 of the present invention and Comparative Examples 3-6, respectively; Figure 3 The SEM images of the catalysts prepared in Example 1 and Comparative Examples 2-6 are shown in Figure 1. (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; Figure 4 TEM images of the catalysts prepared in Example 1 and Comparative Examples 2-3, respectively. (a) 10% Ni-S2O8 2 / ZrO2, (b) 0.5%Ru-S2O8 2 / ZrO2, (c) 10%Ni-0.5%Ru-S2O8 2- / ZrO2; Figure 5 The average particle size diagram of the catalysts prepared in Example 1 of the present invention and Comparative Examples 2-3, (a) 10% Ni-S2O8 2 / ZrO2, (b) 0.5%Ru-S2O8 2 / ZrO2, (c) 10%Ni-0.5%Ru-S2O8 2- / ZrO2; Figure 6 10%Ni-0.5%Ru-S2O8 prepared in Example 1 of the present invention 2- HRTEM and SAED patterns of / ZrO2 catalyst; Figure 7 10%Ni-0.5%Ru-S2O8 prepared in Example 1 of the present invention 2- HAADF-STEM image (j) and element distribution map (ei) of / ZrO2 catalyst; Figure 8 The XPS graphs of the catalysts prepared in Example 1 and Comparative Examples 2-3 are shown in Figure 1. (a) 10% Ni-S2O8 2 Ni 2p / ZrO2 3 / 2 XPS spectrum, (b) 10%Ni-0.5%Ru-S2O8 2- Ni 2p / ZrO2 3 / 2 XPS spectrum, (c) 0.5%Ru-S2O8 2 Ru 3d / ZrO2 5 / 2 XPS spectrum, (d) 10%Ni-0.5%Ru-S2O8 2- Ru 3d / ZrO2 5 / 2 XPS spectrum; Figure 9 FT-IR spectra of the catalysts prepared in Example 1 of the present invention and Comparative Examples 2-3, respectively; Figure 10 NH3-TPD spectra of the catalysts prepared in Example 1 and Comparative Example 3 of the present invention, respectively; Figure 11 This is a schematic diagram of the effects of different reaction conditions on the hydrogenation conversion of diphenyl ether, (a) is the effect of temperature; (b) is the effect of pressure; (c) is the effect of reaction time; and (d) is the effect of catalyst dosage. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 A nickel-ruthenium-based solid superacid catalyst 10%Ni-0.5%-S2O82- The preparation method of ZrO2 comprises the following steps: S1. Dissolve 0.12 g (NH4)2S2O8 in methanol solution and stir until completely dissolved. Then add 1 g ZrO2 to the solution and continue stirring and ultrasonicating for 10 min. Then, stir magnetically for 8 h. After filtering, place in a vacuum oven at 110 o C overnight, and after the solid cooled, ground into powder and placed in a muffle furnace at 3 o The temperature was programmed to 550°C / min o C and calcined for 3 h to obtain S2O8 2- / ZrO2; S2. Prepare nickel-ruthenium-based hydrogenation catalyst by incipient wetness impregnation method: weigh 0.2755g nickel nitrate and 0.0063g ruthenium trichloride hydrate and dissolve them in 15mL deionized water as metal precursors, ultrasonicate for 10min, and then add 0.5g S2O8 2- / ZrO2, continue ultrasonication for 15 min, add 50mL 10 mg / mL NaBH4 solution for reduction, the solution changes from light green to dark black; filter the mixture, and then dry in a vacuum oven at 110 o C was dried overnight and ground to obtain a nickel-based solid superacid catalyst, which was labeled as 10%Ni-0.5%Ru-S2O8 according to the metal loading of Ni and Ru. 2- / ZrO2.

[0022] Example 2 A nickel-ruthenium-based solid superacid catalyst 10%Ni-0.1%Ru-S2O8 2- / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is that in step S2, "0.2755g nickel nitrate and 0.0013g ruthenium trichloride hydrate are weighed and dissolved in 15 mL deionized water as a metal precursor", and the other steps remain consistent with Example 1.

[0023] Example 3 A nickel-ruthenium-based solid superacid catalyst 10%Ni-1%Ru-S2O8 2- / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is that in step S2, "0.2755g nickel nitrate and 0.013g ruthenium trichloride hydrate are weighed and dissolved in 15 mL deionized water as a metal precursor", and the other steps remain consistent with Example 1.

[0024] Comparative Example 1 A kind of S2O8 2- / ZrO2 catalyst preparation method, which is consistent with step S1 in Example 1.

[0025] Comparative Example 2 A ruthenium-based solid acid catalyst 0.5%Ru-S2O8 2 / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is 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", and the other steps remain consistent with Example 1.

[0026] Comparative Example 3 A nickel-based solid acid catalyst 10%Ni-S2O8 2 / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is that no ruthenium trichloride hydrate is added in step S2, and the other steps remain consistent with Example 1.

[0027] Comparative Example 4 A nickel-cobalt based solid acid catalyst 10%Ni-1%Co-S2O8 2 / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is that in step S2, "0.2755g nickel nitrate and 0.0158g cobalt nitrate are weighed and dissolved in 15 mL deionized water as a metal precursor", and the other steps remain consistent with Example 1.

[0028] Comparative Example 5 A nickel-gallium-based solid acid catalyst 10%Ni-1%Ga-S2O8 2 / ZrO2 preparation method, the difference between this method and Example 1 is that in step S2, "0.2755g nickel nitrate and 0.0099g gallium nitrate are weighed and dissolved in 15 mL deionized water as a metal precursor", and the other steps remain consistent with Example 1.

[0029] Comparative Example 6 A nickel-iron based solid acid catalyst 10%Ni-1%Fe-S2O8 2 / ZrO2 preparation method, the difference between the steps of this method and those in Example 1 is that in step S2, "0.2755g nickel nitrate and 0.0221g ferric nitrate are weighed and dissolved in 15 mL deionized water as a metal precursor", and the other steps remain consistent with Example 1.

[0030] 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.

[0031] Table 1 Physical structure properties of catalysts S BET : total specific surface area;S meso : mesopore surface area; S micro : micropore surface area; V t : total pore volume; V meso : mesopore volume; V micro : micropore volume; D ave : Average pore size a The total specific surface area was calculated according to the BET method. b The total pore volume is calculated at a relative pressure of P / P0=0.99 c The average pore size is calculated according to the BJH method d. Subtraction calculation Depend on Figure 1 As shown in a, the N2 adsorption and desorption isotherms of all catalysts show similar characteristic curves. The adsorption and desorption curves basically coincide with each other, and no obvious hysteresis phenomenon is observed. This indicates that the prepared catalyst samples are mainly microporous structures with less mesopore content. The pore size distribution results calculated by the BJH method are shown in Figure 1 As shown in Figure 2, the pore sizes of all catalysts are mainly concentrated in the mesoporous range of 2-10 nm, which indicates that the small amount of pores in the sample are mainly mesopores. According to the data analysis of Table 1, whether it is a pure solid superacid carrier or a catalyst after loading metal, its total specific surface area and total pore volume are relatively small. In addition, the loading of bimetallic does not significantly change the specific surface area of ​​the catalyst. Based on the above results, it can be concluded that the pore structure of the catalyst has little effect on its hydrogenation performance. The XRD test results of the samples prepared in Examples 1-3 of the present invention and Comparative Examples 3-6 are shown in Figure 2. Figure 2 For 10%Ni-1%Co-S2O8 2- / ZrO2 and 10%Ni-1%Co-S2O8 2- / ZrO2 catalyst, it can be observed that the 2θ value is 28.2 o , 50.0 o The characteristic diffraction peak of ZrO2 gradually weakened and the crystallinity decreased, while the characteristic diffraction peak of ZrO2 of the catalyst prepared by introducing the second metal Fe, Ru or changing the second metal loading did not change significantly. All samples were at 44.5 o , 51.8 o and 76.3 oCharacteristic peaks of Ni appear at 2θ, corresponding to the (111), (200), and (220) crystal planes of Ni, respectively. Due to the low loading of the second metal, no corresponding characteristic diffraction peaks are observed. This is because the interaction between metals improves the dispersion of metal particles, resulting in the bimetallic catalyst exhibiting better catalytic activity than the single metal Ni-based catalyst.

[0032] The SEM images of the samples prepared in Example 1 and Comparative Examples 2-6 are as follows: Figure 3 As shown, the monometallic Ni-based catalyst exhibits a honeycomb-like structure with numerous micropores and mesopores distributed on the surface. In contrast, the monometallic Ru-based catalyst exhibits an irregular, blocky structure with a relatively smooth surface. The morphologies of the bimetallic catalysts prepared by introducing secondary metals such as Ru, Fe, Ga, and Co are relatively similar, with no significant changes. All exhibit a loose, porous structure, which greatly facilitates the dispersion of the metal particles.

[0033] In order to gain a deeper understanding of the microstructural characteristics of the catalyst, the present invention conducted TEM characterization. Figure 4 and Figure 5 Display, 10%Ni-S2O8 2- / ZrO2 and 0.5%Ru-S2O8 2- TEM images of the Ni-S2O8 / ZrO2 catalysts showed uniform distribution with average particle sizes of 16.1 nm and 9.64 nm, respectively. 2- After introducing 0.5% Ru metal into / ZrO2, the average metal particle diameter of the catalyst was reduced to about 12.45 nm, indicating that the addition of Ru significantly reduced the size of the metal particles. The study believes that the synergistic effect between Ni and Ru not only helps to improve the dispersion of the metal components, but also effectively inhibits the agglomeration of the metal, making its particle size distribution more uniform. The size and morphology of metal particles or clusters have an important influence on the activity of metal catalysts. Reducing the size of metal particles or reducing the degree of aggregation usually helps to improve the catalytic performance of the catalyst. Based on Figure 6 Medium 10%Ni-0.5%Ru-S2O8 2- The HRTEM characterization results of the / ZrO2 catalyst show that the diffraction spots in the SAED and FFT patterns are mainly derived from the lattice diffraction of Ru species. The calculation shows that the spacing between two adjacent planes is 0.214 and 0.234 nm, which are respectively related to Ru 0 The (002) and (100) crystal planes of the species correspond to each other. According to the HAADF-STEM characterization results ( Figure 7 j), 10%Ni-0.5%Ru-S2O8 2-The metal nanoparticles in the / ZrO2 catalyst are highly dispersed on the support surface, and the particle size distribution is narrow. At the same time, element surface scanning analysis further confirmed that ( Figure 7 The five elements (Ni, Ru, S, Zr, and O) are uniformly distributed on the catalyst surface. Research has shown that the size distribution and dispersion of metal particles are key factors influencing the hydrogenation activity of catalysts. Generally speaking, smaller metal particle size and higher dispersion effectively increase the number of surface active sites, thereby improving the catalytic efficiency of the reaction and achieving superior catalytic performance.

[0034] 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 calibrated using the C 1s peak (C-C bond, 284.8 eV). Figure 8 It shows that in 10%Ni-S2O8 2- Ni 2p / ZrO2 3 / 2 In the XPS spectrum, the peak at 852.1 eV corresponds to metallic Ni 0 , and 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 of the sample after it is exposed to air and comes into contact with oxygen and moisture. However, in the case of the bimetallic catalyst 10%Ni-0.5%Ru-S2O8 2- / ZrO2, Ni 2p 3 / 2 Ni in the spectrum 0 The binding energy rises to 852.7 eV. 2- In the / ZrO2 catalyst, Ru 3d 5 / 2 Metal Ru in the spectrum 0 The binding energy of bimetallic 10%Ni-0.5%Ru-S2O8 is 281.8 eV. 2- / Ru 3d in ZrO2 5 / 2 The electron binding energy of the energy spectrum shows a decrease of 0.6 eV. In addition, due to the Ru 3d 3 / 2 Track Metal Ru 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 The analysis results show that the strong interaction between Ni and Ru promotes the transfer of electrons from Ni to Ru, which leads to the 0 The reduction of binding energy and Ni 0 Increase in binding energy.

[0035] Figure 9The infrared spectra in Figure 2 show that the three catalysts prepared in Example 1 of the present invention and Comparative Examples 2-3 respectively exhibit similar infrared absorption peaks, indicating that they have the same functional group structure. Compared with the single metal Ni-based catalyst, the single metal Ru-based catalyst has the highest infrared absorption peaks at 1278, 1635 and 3420 cm -1 The absorption peak at is significantly weakened. In addition, after loading the second metal Ru, the bimetallic catalyst also shows a similar change trend, indicating that the introduction of Ru inhibits the stretching and bending vibrations of the OH bond generated after the catalyst absorbs water, but does not significantly change the basic structure of the catalyst.

[0036] The acidity of the two samples prepared in Example 1 and Comparative Example 3 of the present invention was systematically characterized by NH3-TPD technology. In this method, the NH3 desorption peak area can be used to quantify the acid amount, while the desorption temperature reflects the acid strength. The specific results are as follows: Figure 10 Compared with the single metal Ni-based solid superacid catalyst, the Ni-Ru bimetallic catalyst o There is no NH3 desorption peak at C, indicating that there is no weak acid site; at the same time, 718 o The smaller desorption peak at C representing the strong acid site also disappeared. o A new desorption peak appeared at C, indicating that the introduction of metal Ru increased the medium and strong acid sites of the catalyst. In addition, the desorption peak representing the strong acid site shifted from 604 o C shifted to the low temperature zone.

[0037] Example 4: Hydrogenation application of the catalysts prepared in Examples 1-3 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 in the reactor. After sealing, the remaining air was removed by passing 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 desired reaction temperature (140 o C) and maintained under vigorous stirring at 800 rpm for a period of time (120 min). After the experiment, the reaction system was naturally cooled to room temperature and the pressure was released. The reaction mixture was filtered to remove the catalyst, and the resulting organic phase was analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-mass spectrometry (GC).

[0038] Table 2 Catalytic performance of different catalysts for diphenyl ether hydrogenation The data in Table 2 above show that when no catalyst is added or only S2O8 is used 2-In the blank experiment of ZrO2 support, the conversion efficiency of diphenyl ether in the reaction system was extremely low, and the conversion rate was close to zero. However, after loading metal Ni, 10%Ni-S2O8 2- / ZrO2 catalyst could achieve 49.1% conversion of diphenyl ether under the condition of 140 o C, 1 MPa H2, 2 h, mainly generating benzene, cyclohexane and cyclohexanol and other products, indicating that the reaction path is mainly hydrogenolysis. In order to improve the catalytic activity of the catalyst, the second metal Co, Fe, Ga and Ru was introduced to modify it. It can be observed that compared with single metal Ni-based catalyst, the catalytic effect of Ni-Ru and Ni-Co bimetallic catalysts is significantly improved under the same reaction conditions, and the conversion rate of diphenyl ether reaches 100% and 75.6% respectively. On the contrary, Ni-Fe and Ni-Ga bimetallic catalysts inhibit the catalytic activity of the reaction, and the conversion rate of diphenyl ether decreases to 39.6% and 40.8%. On this basis, the influence of different Ru addition amounts on the reaction was further discussed. The results show that when 0.5% Ru metal is introduced, 10%Ni-0.5%Ru-S2O8 2- / ZrO2 catalyst exhibits very good catalytic performance, can achieve complete conversion of diphenyl ether, and benzene, cyclohexane and cyclohexanol are still the main products, and the reaction path has not changed significantly. In addition, when the Ru addition amount increases to 1%, the conversion rate of diphenyl ether remains unchanged. 10%Ni-0.5%Ru-S2O8 2- / ZrO2, the high catalytic activity can be attributed to the strong interaction between metal Ni and Ru, which reduces the metal particle size and improves the metal dispersion. This conclusion is verified by XRD, SEM and TEM characterization methods.

[0039] According to the above research results, 10%Ni-0.5%Ru-S2O8 2- / ZrO2 catalyst exhibits high catalytic activity in the hydrogenolysis reaction of C-O bond in diphenyl ether. However, the process of catalytic hydrogenolysis reaction is affected by many factors, so further research will be carried out on the specific influence of different factors on hydrogenolysis reaction.

[0040] Example 5: Influence of different solvents on hydrogenation conversion of diphenyl ether The process is consistent with Example 4, except that different solvents are used.

[0041] Table 3 Hydrogenation of diphenyl ether under different solvents Reaction conditions: 100 mg of diphenyl ether, 40 mg of catalyst 10%Ni-0.5%Ru-S2O8 2- / ZrO2, 20 mL of solvent, 140 oC, 2 h, 1 MPa H2.

[0042] In catalytic reactions, the choice of solvent often has a significant impact on the reaction process. In order to reveal the effect of solvent on the conversion of diphenyl ether, 10% Ni-0.5% Ru-S2O8 was used in a H2 atmosphere. 2- The influence of solvent effects on the diphenyl ether (DE) hydrogenation conversion process was investigated using a ZrO2 / ZrO2 catalyst system. The specific experimental results are shown in Table 3. When methanol, ethanol, and tetralin were used as solvents, the catalyst activity was low, resulting in almost no conversion of DE. However, when n-hexane was used as the solvent, the conversion of DE was significantly improved, reaching 32.5%. This is due to the higher solubility of H2 in alkanes than in alcohols. The catalyst exhibited very high catalytic activity when using isopropanol as the solvent, achieving complete conversion of DE under the same reaction conditions. Isopropanol plays a dual role in this reaction system: it serves as the reaction solvent and, through dehydrogenation and oxidation, produces acetone, simultaneously releasing a large amount of active hydrogen species. These in situ generated active hydrogen species synergistically with the hydrogen source provided by H2, participating in the DE hydrogenation process, significantly improving the reaction efficiency.

[0043] Using isopropanol as solvent, the effects of different reaction parameters (reaction temperature, hydrogen pressure, reaction time, and catalyst dosage) on the performance of 10%Ni-0.5%Ru-S2O8 2- Effect of ZrO2 catalyst on diphenyl ether conversion process.

[0044] Example 6: Effect of reaction temperature on diphenyl ether hydrogenation conversion The process is consistent with that of Example 4, except that the reaction temperature is changed.

[0045] Reaction conditions: 100 mg diphenyl ether, 40 mg catalyst 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 2 h, 1 MPa H2.

[0046] Example 7: Effect of hydrogen pressure on diphenyl ether hydrogenation conversion The process is consistent with that of Example 4, except that the hydrogen pressure is changed.

[0047] 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.

[0048] Example 8: Effect of reaction time on diphenyl ether hydrogenation conversion The procedure was consistent with Example 4, except that different reaction time was changed.

[0049] Reaction condition: 100 mg diphenyl ether, 40 mg catalyst 10%Ni-0.5%Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 140 o C, 1 MPa H2.

[0050] Example 9: Effect of catalyst dosage on the hydroconversion of diphenyl ether The procedure was consistent with Example 4, except that different catalyst dosage was changed.

[0051] Reaction condition: 100 mg diphenyl ether, catalyst 10%Ni-0.5%Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 1 MPa H2, 140 o C, 2 h.

[0052] Figure 11 The experimental data of a revealed the effect of different reaction temperatures on the conversion of diphenyl ether catalyzed by 10%Ni-0.5%Ru-S2O8 2- / ZrO2. In the lower temperature range (110-140 o C), the conversion of diphenyl ether showed a rapid upward trend with the increase of temperature, and reached complete conversion under the reaction condition of 140 o C, the main products were benzene, cyclohexane and cyclohexanol, and their content gradually increased with the increase of temperature. At the same time, the yield of cyclohexanol was always higher than that of cyclohexane, indicating that phenol was more prone to aromatic ring hydrogenation than benzene. In addition, a small amount of monocyclic hydrogenation product CPE and bicyclic hydrogenation product OCE were also detected. When the temperature rose to 150 o C, the conversion of diphenyl ether remained unchanged, but the yield of cyclohexane increased due to the hydrogenation of part of benzene. Throughout the reaction process, the yield of CPE showed a trend of first rising and then falling. In order to avoid the over-hydrogenation of products at high temperature, the optimal reaction temperature for the conversion of diphenyl ether was determined to be 140 o C.

[0053] Figure 11 b explored the mechanism of H2 pressure parameter on the conversion of diphenyl ether catalyzed by 10%Ni-0.5%Ru-S2O8 2- / ZrO2 catalyst. Experimental data showed that lower H2 pressure (0.1 MPa) would result in limited hydrogenolysis ability of the reaction system, leading to lower conversion of diphenyl ether and lower yield of target products. In the reaction condition of 140 oC, under the reaction conditions of 2 h, when the H2 pressure was 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, and complete conversion was achieved at a pressure of 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 in the product showed a gradual downward and upward trend, respectively, while the yield of cyclohexane showed a trend of first decreasing and then increasing. The research results show that lower H2 pressure will lead to lower catalyst activity and promote the accumulation of intermediate products; when the reaction can achieve complete conversion, higher H2 pressure will lead to excessive consumption of H2, resulting in a waste of resources. Therefore, the present invention determines 1 MPa as the optimal reaction hydrogen pressure condition.

[0054] In determining the optimal reaction temperature (140 o C) and hydrogen pressure (1 MPa) parameters, the 10%Ni-0.5%Ru-S2O8 2- The effect of reaction time on the distribution of conversion products during the conversion of diphenyl ether catalyzed by ZrO2 was studied to explore the internal mechanism and pathway of the reaction. Figure 11 c experimental results show that 10%Ni-0.5%Ru-S2O8 2- The ZrO2 / ZrO2 catalyst exhibited excellent catalytic performance within a reaction time of 0.5-2.5 h. In the initial reaction phase (0.5 h), the conversion of diphenyl ether reached 89.9%. This conversion continued to increase with increasing reaction time, reaching complete conversion after 1.5 h and remaining stable thereafter. The formation of the dicyclic hydrogenation product, OCE, was virtually absent throughout the reaction. Product distribution analysis confirmed the primary reaction pathway for diphenyl ether conversion: Initially, diphenyl ether selectively hydrogenated to form a CPE intermediate. Subsequently, CPE primarily hydrogenated through the CO bond to form monocyclic products such as benzene, cyclohexane, and cyclohexanol. Only a small amount of CPE was further hydrogenated to OCE. After comprehensive consideration of various factors, 2 h was determined to be the optimal reaction time.

[0055] The amount of catalyst added has an important influence on the efficiency of diphenyl ether hydrogenolysis reaction. Figure 11 d experimental results show that when 10%Ni-0.5%Ru-S2O8 2-The conversion efficiency of diphenyl ether gradually increased when the ZrO2 catalyst dosage varied from 10 to 50 mg, achieving complete conversion at 40 mg and remaining stable thereafter. At 10 mg, the conversion of diphenyl ether was only 50.4%. This is primarily due to the fact that lower catalyst dosages reduce the amount of active metal available, resulting in fewer active sites available for the reaction. This not only slows the rate of active hydrogen generation but also reduces the number of sites available for reactant adsorption, thus affecting the efficiency of hydrogenolysis of the CO bond in diphenyl ether. While the conversion of diphenyl ether remained stable with increasing catalyst dosage, some of the benzene in the product was gradually hydrogenated to form cyclohexane. Based on these results, 40 mg was determined to be the optimal catalyst dosage for the reaction.

[0056] Example 10: 10%Ni-0.5%Ru-S2O8 2- Application of ZrO2 in catalytic hydrogenation of different substrates The process is consistent with that of Example 4, except that different substrates, ie, different coal model compounds, are used.

[0057] Table 4 10%Ni-0.5%Ru-S2O8 2- / ZrO2 catalyzes hydrogenation of different substrates Reaction conditions: 100 mg of substrate, i.e., coal model compound, 40 mg of 10% Ni-0.5% Ru-S2O8 2- / ZrO2, 20 mL isopropanol, 1 MPa H2.

[0058] Based on 10%Ni-0.5%Ru-S2O8 2- The excellent catalytic activity of the Ni / ZrO2 catalyst in the hydrogenolysis of DPE was further expanded to investigate the catalytic conversion performance of the catalyst for a variety of other lignite model compounds. By systematically studying the hydrogenolysis reactions of typical model compounds such as benzyl phenyl ether and dibenzyl ether, the application potential of the catalyst in the conversion of coal-derived aromatic ether compounds was comprehensively evaluated. The conversion rates and product distribution results of the relevant model compounds are shown in Table 4. Under the respective experimental conditions, 10%Ni-0.5%Ru-S2O8 2-The Ni / ZrO2 catalyst exhibited excellent catalytic activity for a variety of 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 ethers was mainly achieved through a selective CO bond cleavage pathway, and the products were mostly monocyclic aromatic compounds. The results showed that under relatively mild reaction conditions, 10% Ni-0.5% Ru-S2O8 2- / 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: The following steps are involved: S1. Dissolve (NH4)2S2O8 in methanol and stir until completely dissolved to obtain ammonium persulfate methanol solution; add ZrO2 to the solution and continue stirring and ultrasonicating for 8-12 min, then stir for 7-9 h, filter and dry the precipitate in a vacuum oven overnight, grind into powder after the solid cools, and then o C and calcined for 3 h to obtain S2O8 2- / ZrO2; S2. Prepare nickel-ruthenium-based hydrogenation catalyst by incipient wetness impregnation method: weigh nickel salt and ruthenium salt and dissolve them in deionized water to obtain metal precursor solution, ultrasonicate for 8-12 min, and then add S2O8 2- / ZrO2, continue ultrasonication for 10-20 min, then add NaBH4 solution for reduction, and the solution changes from light green to dark black; the mixture is filtered, vacuum dried, and ground to obtain a nickel-ruthenium-based solid superacid hydrogenation catalyst.

2. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1, wherein: In step S2, the concentrations of nickel salt and ruthenium salt in the metal precursor solution are 1 M and 0.1 M, respectively; and the loading amounts of Ni and Ru in the nickel-ruthenium-based solid superacid hydrogenation catalyst are 10 wt% and 0.5-1 wt%, respectively.

3. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1 or 2, wherein: 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.

4. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1 or 2, wherein: In step S1, the concentration of ammonium persulfate methanol solution is 0.5 M; the mass ratio between (NH4)2S2O8 and ZrO2 is 3:25; o The temperature was programmed to 550°C / min o C and calcined for 3 h.

5. The method for preparing a nickel-ruthenium-based solid superacid hydrogenation catalyst according to claim 1 or 2, wherein: In steps S1 and S2, after filtering, the precipitate is placed in a vacuum oven at 110 o C and dried overnight.

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

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

8. The use according to claim 7, characterized in that The specific application process is as follows: coal model compound, nickel-ruthenium-based solid superacid hydrogenation catalyst and solvent are placed in a reactor, sealed, and hydrogen is introduced to remove the residual air; then the reactor is pressurized to 0.1-2.0 MPa with hydrogen at room temperature, and the reaction temperature is controlled at 110-150 o C, and reacting for 30-150 minutes under stirring; the mass ratio between the nickel-ruthenium-based solid superacid hydrogenation catalyst and the coal model compound is 1:(2-10); after the reaction, 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 analyzed by gas chromatography-mass spectrometry and gas phase analysis.

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

10. The use according to claim 8, characterized in that The coal model compound is one of diphenyl ether, benzyl phenyl ether, phenoxyethylbenzene, dibenzyl ether, 4-phenoxyphenol and p-xylyl ether; and the solvent is isopropyl alcohol or n-hexane.

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