Ni / TiO2-ZrO2 composite catalyst with heterojunction structure as well as preparation method and application of Ni / TiO2-ZrO2 composite catalyst

Abstract

The invention belongs to the technical field of catalyst preparation, and particularly discloses a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure as well as a preparation method and application of the Ni / TiO2-ZrO2 composite catalyst. The composite catalyst comprises a zirconium titanate composite oxide carrier and a Ni metal active component loaded on the carrier, wherein the Ti element and the Zr element in the zirconium titanate composite oxide carrier form a zirconium titanate structure with a heterojunction structure through chemical bonding; the Ni / TiO2-ZrO2 composite catalyst is prepared by one-step reduction heat treatment. The one-step reduction heat treatment method is adopted, the TiO2-ZrO2 composite carrier with the heterostructure characteristic is directly prepared, meanwhile, loading and reduction of nickel are completed in the same step, and therefore the hydrodeoxygenation catalyst with better performance is obtained. The Ni / TiO2-ZrO2 composite carrier disclosed by the invention is high in activity and selectivity in the hydrodeoxygenation reaction of the bio-oil, and the preparation method is simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst preparation, in particular to a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure and a preparation method and application thereof. BACKGROUND

[0002] With the increasing demand for renewable energy, the conversion of lignocellulosic biomass into higher quality liquid fuels has become a focus of research and industrial development. Lignin, as the main aromatic component in biomass, produces a large amount of phenolic compounds (such as guaiacol, eugenol, etc.) during pyrolysis or degradation. However, the crude bio-oil obtained has high oxygen content, low calorific value, strong acidity, and unstable chemical properties, and cannot be directly used as fuel. Therefore, hydrogenation deoxygenation (HDO) technology is needed to reduce its oxygen content and improve fuel quality, and an efficient and stable catalyst is the key to achieving this goal.

[0003] In HDO reactions, supported metal catalysts play an important role: the metal is responsible for hydrogen activation and hydrogenation, while the support affects the dispersion of the metal and the acidity, thereby affecting the deoxygenation reaction effect. TiO2 has certain oxygen vacancies and metal interactions, while ZrO2 has good thermal stability and adjustable acidity. If the two are combined, it is expected to simultaneously exert the advantages of both materials.

[0004] However, traditional TiO2-ZrO2 composite supports usually need to be co-precipitated and then calcined at high temperatures in air (generally higher than 800℃) to form a stable structure. This high-temperature treatment easily causes a decrease in specific surface area, damage to pore structure, and is not conducive to the formation of more active defect sites. At the same time, the process has many steps and high energy consumption. In addition, there is currently no research on the use of TiO2 and ZrO2 precursors to directly interact with each other under relatively mild reduction conditions, in-situ formation of non-complete crystallization carriers with heterostructures and defects, and their use in the system for efficient HDO of lignin phenolic compounds.

[0005] Therefore, it is of great significance and application prospect to develop a method for preparing a TiO2-ZrO2 composite support with high specific surface area, rich in oxygen vacancies, and having a synergistic interface, which can be constructed in one step under mild conditions, and used to prepare a high-performance HDO catalyst. SUMMARY

[0006] In view of the above-mentioned problems, this invention provides a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure, its preparation method, and its application. This invention employs a one-step reduction heat treatment method to directly prepare a TiO2-ZrO2 composite support with heterostructure characteristics, simultaneously completing nickel loading and reduction in the same step, thereby obtaining a hydrodeoxygenation catalyst with superior performance. The Ni / TiO2-ZrO2 composite support of this invention exhibits high activity and selectivity in the hydrodeoxygenation reaction of bio-oils, and its preparation method is simple.

[0007] To address the aforementioned problems, this invention provides a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure. The Ni / TiO2-ZrO2 composite catalyst comprises a zirconium titanate (ZrTiO4) composite oxide support and a Ni metal active component supported on the support. The Ti element and Zr element in the zirconium titanate (ZrTiO4) composite oxide support are chemically bonded to form a zirconium titanate (ZrTiO4) structure with a heterojunction. The Ni / TiO2-ZrO2 composite catalyst is prepared by a one-step reduction heat treatment.

[0008] Traditional TiO2 or ZrO2 supported catalysts suffer from a trade-off between good metal particle dispersion and support acidity, and the preparation process requires high-temperature crystallization, leading to a decrease in specific surface area and severely limiting catalytic performance. In this application, the Ni / TiO2-ZrO2 catalyst achieves a synergistic effect mechanism between Ni metal sites and support oxygen vacancies and acidic sites. Furthermore, thanks to the unique heterojunction structure formed by one-step reduction heat treatment, the TiO2-ZrO2 composite support provides high specific surface area, abundant oxygen vacancies, and tunable acidity. The formation of the Ti-O-Zr heterojunction enhances support stability, enabling the catalyst to maintain the dispersion and stability of active sites under high-temperature hydrodeoxygenation conditions.

[0009] Preferably, the average particle size of the Ni metal is 11.30-12.49 nm, and the loading of the Ni metal is 19-21 wt% of the Ni / TiO2-ZrO2 composite catalyst.

[0010] Preferably, the molar ratio of Ti to Zr in the Ni / TiO2-ZrO2 composite catalyst is 0.95:1.85-2.04; and the BET specific surface area of ​​the Ni / TiO2-ZrO2 composite catalyst is 175-195 m². 2 / g.

[0011] Based on the same inventive concept, this invention also provides a method for preparing the Ni / TiO2-ZrO2 composite catalyst with heterojunction structure described above, comprising the following steps:

[0012] S1. A composite precursor suspension is obtained by co-precipitating titanium source, zirconium source, nickel salt and sodium hydroxide.

[0013] S2. The composite precursor suspension is subjected to aging, solid-liquid separation, washing, and drying to obtain the catalyst precursor;

[0014] S3. The precursor is subjected to a one-step reduction heat treatment in a reducing atmosphere to obtain a one-step reduction heat treatment.

[0015] In the preparation method of this invention, the Ni metal sites and TiO2-ZrO2 are loaded by mixing the nickel source with the titanium source and the zirconium source through a co-precipitation method, and then simultaneously forming the metallic Ni and the support structure through a one-step reduction heat treatment. The above method of this invention is conducive to the uniform dispersion of metallic Ni nanoparticles on the surface and in the pores of the composite support. At the same time, the heterojunction structure and abundant oxygen vacancies of the TiO2-ZrO2 support help anchor and stabilize the metal particles, forming a highly dispersed and stable catalytic system.

[0016] Preferably, in step S1, the titanium source is at least one of TiO2, TiCl4, and TiOSO4; the zirconium source is at least one of zirconium oxychloride octahydrate, zirconium nitrate pentahydrate, zirconium sulfate, and basic zirconium carbonate; and the nickel source is at least one of nickel nitrate hexahydrate, nickel acetate tetrahydrate, nickel sulfate hexahydrate, and nickel chloride hexahydrate.

[0017] For example, the titanium source is TiO2, the zirconium source is zirconium oxychloride octahydrate, and the nickel source is nickel nitrate hexahydrate.

[0018] Preferably, in step S1, the mass ratio of the titanium source, zirconium source, nickel salt and sodium hydroxide is 1:7.1-8.6:3.6-4.4:4.4-5.3; and the pH value of the composite precursor suspension is 9.5-10.5.

[0019] For example, the titanium source is 0.24-0.26g, the zirconium source is 1.86-2.06g, the nickel salt is 0.94-1.04g, and the sodium hydroxide is 1.14-1.26g.

[0020] In step S1, for example, 0.24-0.26 g of TiO2 powder and 1.86-2.06 g of zirconium oxychloride octahydrate (ZrOCl2·8H2O) are added to 14.2-15.8 mL of deionized water and stirred to mix; 0.94-1.04 g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O) is dissolved in 9.5-10.5 mL of deionized water to form a salt solution, and 1.14-1.26 g of sodium hydroxide is dissolved in 9.5-10.5 mL of deionized water to form an alkaline solution; under stirring, the salt solution and the alkaline solution are simultaneously added dropwise to the mixture of TiO2 and zirconium salt, and the pH of the mixed solution is controlled to be 9.5-10.5 to obtain a composite precursor suspension.

[0021] Preferably, in step S2, the aging temperature is 75-85℃ and the time is 11.4-12.6h; the drying time is 11.4-12.6h.

[0022] Preferably, in step S3, the reducing atmosphere is hydrogen gas with a flow rate of 76-84 mL / min; the one-step reduction heat treatment involves raising the temperature from room temperature to 570-630℃ at a rate of 4.75-5.25℃ / min, and reducing at this temperature for 0.95-1.05 h.

[0023] Based on the same inventive concept, the present invention also provides the application of the Ni / TiO2-ZrO2 composite catalyst with heterojunction structure described above or the Ni / TiO2-ZrO2 composite catalyst with heterojunction structure prepared by any of the preparation methods described above in the hydrodeoxygenation reaction of light phenolic components.

[0024] Preferably, the temperature of the hydrodeoxygenation reaction is 240-260℃, the time is 3-5h, and the pressure is 1-2MPa; the substrate of the light phenolic component includes one or more of phenol, guaiacol, and eugenol, and the mass ratio of the substrate of the light phenolic component to the Ni / TiO2-ZrO2 composite catalyst is 5-15:2-10.

[0025] Preferably, in the above applications, a solvent is also required, the solvent including n-octane.

[0026] For example, the substrate of the light phenolic component is 0.05-0.15g, the Ni / TiO2-ZrO2 composite catalyst is 0.02-0.10g, and the solvent is 15-25mL.

[0027] The mechanism of action of this invention is as follows: the highly dispersed Ni metal sites are responsible for efficient hydrogenation, while the abundant oxygen vacancies and acidic sites at the heterojunction interface of the support promote the adsorption and breaking of CO bonds. The two work synergistically through metal-support electronic interactions, significantly improving the overall efficiency of hydrodeoxygenation. Simultaneously, the one-step constructed TiO2-ZrO2 composite support has a stable structure, thereby improving the catalyst's anti-sintering performance and cycle stability.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) This invention achieves simultaneous generation of active metal Ni and construction of TiO2-ZrO2 heterojunction support structure during the reduction process in a one-step manner, eliminating the need for a separate high-temperature crystallization step of the support. This simplifies the process while ensuring efficient metal dispersion and high specific surface area of ​​the support, avoiding the destruction of active sites caused by multi-step processing. This method can construct a strong metal-support synergistic mechanism, such as the efficient hydrogenation of Ni sites combined with the deoxygenation promoted by oxygen vacancies and acid sites on the support. Through process innovation and structural optimization, it breaks through existing bottlenecks and provides a new path for upgrading the performance of Ni-based catalysts.

[0030] (2) The Ni / TiO2-ZrO2 catalyst prepared in this invention exhibits a conversion rate of nearly 100% and a cyclohexane selectivity of more than 99% in the hydrodeoxygenation reaction of lignin-derived phenols. In Example 1, the Ni / TiO2-ZrO2 catalyst can increase the hydrocarbon content from 12.2% to 85.2% in the real lignin oil upgrading process, and has good cycle stability, indicating that this one-step heterojunction catalyst strategy has high efficiency and stability and has broad industrial application prospects.

[0031] (3) Based on TEM images and particle size distribution statistics ( Figure 2 The results show that the Ni / TiO2-ZrO2 catalyst of the present invention exhibits good metal particle dispersion, with an average particle size of approximately 11.3-12.5 nm, and the particle distribution is relatively uniform with no obvious agglomeration. High-resolution TEM images (…) further demonstrate this. Figure 2 ) and XRD pattern ( Figure 1 This further confirms that the TiO2 and ZrO2 of the present invention form an inter-intercalated heterojunction structure rather than a simple physical mixture, which provides a structural basis for its excellent catalytic performance. Attached Figure Description

[0032] Figure 1 The XRD patterns are of the catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention.

[0033] Figure 2These are TEM images showing the microstructure, dispersion, and size distribution characteristics of the catalysts prepared in Example 1 and Comparative Examples 1-2 of the present invention; wherein, (a) is a TEM image (scale bar 5 nm) of the Ni / TiO2 catalyst prepared in Comparative Example 1; (b) is a TEM image (scale bar 5 nm) of the Ni / ZrO2 catalyst prepared in Comparative Example 2; (c) is a TEM image (scale bar 5 nm) of the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1; and (d) is a TEM image (scale bar 5 nm) of the Ni / TiO2 catalyst prepared in Comparative Example 1. (e) TEM image of the Ni / ZrO2 catalyst prepared in Comparative Example 2 (scale bar: 200 nm); (f) TEM image of the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 (scale bar: 200 nm); (g) Size distribution diagram of the Ni / TiO2 catalyst prepared in Comparative Example 1; (h) Size distribution diagram of the Ni / ZrO2 catalyst prepared in Comparative Example 2; (i) Size distribution diagram of the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1;

[0034] Figure 3 The NH3-TPD spectra of the catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention are shown.

[0035] Figure 4 The above are XPS O 1s spectra of the catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention. Detailed Implementation

[0036] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or obtained by known methods.

[0037] To address the problems of cumbersome processing steps required for TiO2-ZrO2 composite supports in existing technologies, and the insufficient activity and selectivity of catalysts supported on them in the hydrodeoxygenation reaction of bio-oils, this invention provides a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure, its preparation method, and its application.

[0038] The following examples and comparative models further illustrate this point.

[0039] Example 1

[0040] A method for preparing a Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure includes the following steps:

[0041] (1) 0.25 g TiO2 powder and 1.9614 g zirconium oxychloride octahydrate (ZrOCl2·8H2O) were added to 15 mL of deionized water and stirred to form a suspension. Under continuous vigorous stirring, a salt solution formed by dissolving 0.9906 g nickel nitrate hexahydrate (Ni(NO3)2·6H2O) in 10 mL of deionized water and an alkaline solution formed by dissolving 1.2 g sodium hydroxide (NaOH) in 10 mL of deionized water were added dropwise at a rate of 0.5 mL / min. The pH of the mixture was controlled to rise to 10 to obtain a composite precursor suspension.

[0042] (2) The obtained composite precursor suspension was aged in an oil bath at 80°C for 12 hours. After the reaction was completed, the product was filtered and washed with deionized water until the filtrate was neutral (pH≈7). The obtained solid was dried at 80°C for 12 hours to obtain the catalyst precursor.

[0043] (3) The above catalyst precursor was placed in a tube furnace and heated to 600°C at a rate of 5°C / min under a pure H2 atmosphere (flow rate 80 mL / min). The temperature was then maintained at this temperature for 1 hour for reduction heat treatment. After the heat treatment, the catalyst was cooled to room temperature under an H2 atmosphere to obtain the Ni / TiO2-ZrO2 composite catalyst (Ni metal sites account for approximately 20% of the total mass of the catalyst, and the TiO2-ZrO2 composite oxide support accounts for approximately 80% of the total mass of the catalyst).

[0044] The specific surface area, total pore volume, and average pore size of the Ni / TiO2-ZrO2 composite catalyst prepared above were measured, and the results are shown in Table 1.

[0045] Table 1:

[0046] It should be noted that the above a The above represents the specific surface area obtained by the BET method. b This indicates the pore size or pore diameter obtained by the BLH method.

[0047] Example 2

[0048] The Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 was applied to the hydrodeoxygenation reaction of light phenolic components, and the steps are as follows:

[0049] 0.05 g of the Ni / TiO2-ZrO2 catalyst prepared in Example 1, 0.1 g of guaiacol, and 20 mL of n-octane were added to a high-pressure reactor, and the reaction was carried out at 250 °C and a hydrogen pressure of 1 MPa for 4 hours. After the reaction was completed, the mixture was cooled to room temperature and samples were taken. The conversion rate of guaiacol and the selectivity of hydrocarbons (cyclohexane, cyclohexanol, and methoxycyclohexanol) in the products were detected by gas chromatography-mass spectrometry (GC-MS), as detailed in Table 2.

[0050] Table 2:

[0051] Example 3

[0052] The difference between this embodiment and Example 2 is that the temperature is 220℃. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 2.

[0053] Example 4

[0054] The difference between this embodiment and Example 2 is that the temperature is 230℃. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 2.

[0055] Example 5

[0056] The difference between this embodiment and Example 2 is that the temperature is 240℃. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 2.

[0057] Example 6

[0058] The difference between this embodiment and Example 2 is that the reaction time is 1 hour. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of hydrocarbons (cyclohexane, cyclohexanol, methoxycyclohexanol) in the products are shown in Table 3.

[0059] Table 3:

[0060] Example 7

[0061] The difference between this embodiment and Example 2 is that the reaction time is 2 hours. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 3.

[0062] Example 8

[0063] The difference between this embodiment and Example 2 is that the reaction time is 3 hours. Other steps and parameters are the same as in Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 3.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that zirconium oxychloride octahydrate (zirconium source) was not added; other steps and parameters were the same as in Example 1. A Ni / TiO2 catalyst was finally prepared.

[0066] The specific surface area, total pore volume, and average pore size of the Ni / TiO2 catalyst prepared above were measured, and the results are shown in Table 1.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 1 is that TiO2 powder (titanium source) was not added; all other steps and parameters were the same as in Example 1. A Ni / ZrO2 catalyst was finally prepared.

[0069] The specific surface area, total pore volume, and average pore size of the Ni / ZrO2 catalyst prepared above were measured, and the results are shown in Table 1.

[0070] Comparative Example 3

[0071] The difference from Example 2 is that the catalyst was replaced with the Ni / TiO2 catalyst prepared in Comparative Example 1. The final conversion rate of guaiacol and the selectivity of hydrocarbons (cyclohexane, cyclohexanol, methoxycyclohexanol) in the products are shown in Table 4.

[0072] Comparative Example 4

[0073] The difference from Example 2 is that the catalyst was replaced with the Ni / ZrO2 catalyst prepared in Comparative Example 2. The final conversion rate of guaiacol and the selectivity of the hydrocarbon cyclohexane in the product are shown in Table 4.

[0074] Table 4:

[0075] As shown in Table 4, the catalysts prepared in Examples 1 and Comparative Examples 1-2 achieved a conversion rate of over 99% for guaiacol, essentially achieving complete conversion. The main products included cyclohexane, cyclohexanol, and methoxycyclohexanol. Notably, when the support was changed from the single TiO2 in Comparative Example 1 / ZrO2 in Comparative Example 2 to the TiO2-ZrO2 composite support in Example 1, the cyclohexane selectivity significantly increased from 4.9% / 51% to 99.4%. This significant improvement mainly stems from the comprehensive advantages of the Ni / TiO2-ZrO2 catalyst in Example 1, including its ZrTiO4 heterostructure and high specific surface area (184.34 m²). 2 The Ni / TiO2 catalyst in Comparative Example 1 possesses abundant oxygen vacancies (51.8%) and more suitable acidity (especially medium-strong acid sites). These factors collectively contribute to a smoother and more efficient hydrogenation and deoxygenation process. In contrast, the Ni / TiO2 catalyst in Comparative Example 1 lacks sufficient oxygen vacancies and acidic sites, resulting in incomplete deoxygenation. While the Ni / ZrO2 catalyst in Comparative Example 2 exhibits better acidity, its smaller pore size and simpler structure limit its overall reaction efficiency. The combined results demonstrate that the TiO2-ZrO2 heterostructure support constructed through a one-step reduction heat treatment in this application can simultaneously optimize multiple activity factors, which is crucial for achieving efficient and highly selective hydrogenation and deoxygenation reactions.

[0076] The above results demonstrate that the Ni / TiO2-ZrO2 catalyst prepared by the one-step reduction heat treatment process of this invention possesses a unique heterojunction structure and highly dispersed active sites, significantly improving the catalyst's hydrodeoxygenation activity and product selectivity. Under conditions of 1 MPa hydrogen pressure and 250℃ for 4 hours, the guaiacol conversion reached 99.9%, and the cyclohexane selectivity reached 99.4%, achieving highly efficient conversion of guaiacol to cyclohexane.

[0077] Performance testing and results analysis

[0078] The catalysts prepared in Example 1 and Comparative Examples 1-2 were analyzed by X-ray diffraction (XRD), and the results are as follows: Figure 1 As shown. By Figure 1It can be seen that the Ni / TiO2 catalyst prepared in Comparative Example 1 exhibits characteristic diffraction peaks of anatase TiO2 at 25.2°, 37.7°, and 48.0°; the Ni / ZrO2 catalyst prepared in Comparative Example 2 exhibits characteristic diffraction peaks of monoclinic ZrO2 at 30.2°, 35.1°, and 50.2°; the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 does not show independent, sharp TiO2 or ZrO2 characteristic peaks, but rather peaks at 24.8° and... A significantly broadened diffraction peak was observed near 30.6°; compared to the (101) plane characteristic peak (25.2°) of the Ni / TiO2 catalyst prepared in Comparative Example 1, the diffraction peak of the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 shifted to a lower angle; compared to the (101) plane characteristic peak (30.2°) of the Ni / ZrO2 catalyst prepared in Comparative Example 2, the diffraction peak of the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 shifted to a higher angle. This phenomenon indicates that during the one-step reduction heat treatment process, Ti... 4+ and Zr 4+ The species intercalate into each other's lattices, forming a Ti-O-Zr bonded heterojunction structure, rather than a simple physical mixture. Furthermore, all catalysts of Example 1 and Comparative Examples 1-2 exhibited weak Ni(111) diffraction peaks at approximately 44.5°, indicating the presence of metallic Ni.

[0079] The catalysts prepared in Example 1 and Comparative Examples 1-2 were analyzed by transmission electron microscopy (TEM), and the results are as follows: Figure 2 As shown. By Figure 2 (g)- Figure 2 (i) It can be seen that, compared with the Ni / TiO2 catalyst prepared in Comparative Example 1 and the Ni / ZrO2 catalyst prepared in Comparative Example 2, the Ni metal nanoparticles on the Ni / TiO2-ZrO2 composite catalyst prepared in Example 1 are more uniformly distributed and have a smaller average particle size (approximately 11.9 nm). Figure 2 (a)- Figure 2 (f) It can be seen that clear lattice fringes can be observed in the Ni / TiO2-ZrO2 catalyst of Example 1. The lattice fringes with spacings of approximately 0.1697 nm and 0.1713 nm were measured and belong to the (111) crystal plane of ZrTiO4 and the (101) crystal plane of ZrO2, respectively. The two phase regions are closely adjacent, which directly confirms the formation of the heterojunction interface between TiO2 and ZrO2. The lattice spacing of the supported Ni particles is approximately 0.2446 nm, which matches the Ni (111) plane. This indicates that the one-step reduction heat treatment method not only successfully constructed the support heterojunction but also effectively promoted the high dispersion of Ni particles.

[0080] The catalysts prepared in Example 1 and Comparative Examples 1-2 were characterized by NH3-TPD, and the results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the Ni / TiO2 catalyst of Comparative Example 1 exhibits weak desorption peaks around 100℃ and 400℃, indicating that its acidity is weak and mainly consists of weak and moderately strong acids. The Ni / ZrO2 catalyst of Comparative Example 2 shows more obvious desorption peaks around 120℃ and 400℃, and its total acidity is higher than that of the Ni / TiO2 catalyst of Comparative Example 1. In contrast, the Ni / TiO2-ZrO2 catalyst of Example 1 exhibits significantly stronger desorption peaks around 130℃ and 420℃. This indicates that the heterojunction structure formed by TiO2 and ZrO2 through a one-step reduction method in this application can synergistically generate richer and stronger acidic sites. These acidic sites, especially moderately strong acid sites, are considered to be key active centers promoting CO bond breaking in the hydrodeoxygenation reaction, providing an important basis for the high deoxygenation selectivity of the catalyst.

[0081] The catalysts prepared in Example 1 and Comparative Examples 1-2 were characterized by XPS, and the results are as follows: Figure 4 As shown. By Figure 4 It can be seen that the O1s spectra of the catalysts prepared in Example 1 and Comparative Examples 1-2 can be fitted with two main peaks: the peak at approximately 529.8 eV belongs to lattice oxygen, while the peak at approximately 531.8 eV belongs to surface oxygen vacancies, hydroxyl groups, and other defective oxygen species. Calculations based on peak area show that the surface oxygen vacancy ratios of the Ni / TiO2 and Ni / ZrO2 catalysts in Comparative Example 1 are 35.1% and 34.3%, respectively; while the surface oxygen vacancy ratio of the Ni / TiO2-ZrO2 catalyst in Example 1 is significantly increased to 51.8%. This result directly demonstrates that the TiO2-ZrO2 heterojunction structure formed through one-step reduction heat treatment can create richer surface oxygen defects. These oxygen vacancies can serve as active sites, promoting the adsorption and activation of reactants, and may optimize electron transfer between the metal and the support, making them one of the key factors in improving hydrodeoxygenation performance.

[0082] The catalysts prepared in Example 1 and Comparative Examples 1-2 were subjected to nitrogen adsorption-desorption tests, and their specific surface area and pore structure parameters were calculated using the BET and BJH methods, respectively. The results are shown in Table 1. As can be seen from Table 1, compared with the Ni / TiO2 catalyst of Comparative Example 1 and the Ni / ZrO2 catalyst of Comparative Example 2, the Ni / TiO2-ZrO2 catalyst of Example 1 possesses a higher specific surface area (184.34 m²). 2 The Ni / ZrO2 catalyst in Comparative Example 2 has the highest specific surface area (197.87 nm) and a moderate average pore size (6.05 nm). 2While the Ni / TiO2 catalyst in Comparative Example 1 had the largest pore size (26.59 nm), its average pore size was relatively small (4.24 nm), which might affect the diffusion of reactant molecules. 2 / g), which limits the exposure of active metal sites. Overall, the Ni / TiO2-ZrO2 in Example 1 exhibits more balanced pore structure parameters, indicating that the TiO2-ZrO2 composite support formed by one-step reduction heat treatment can simultaneously retain the structural advantages of both oxides, constructing a pore structure more suitable for catalytic reactions. A higher specific surface area is beneficial for the dispersion and immobilization of Ni particles, while a moderate pore size distribution facilitates the transport of reactants and products. This result is also consistent with... Figure 1 The heterostructure observed in the XRD is consistent with that of the composite support, indicating that this composite support is not a simple mixture of TiO2 and ZrO2, but a unique structure with ZrTiO4 binding characteristics formed in a one-step process. This structure can improve its pore structure and surface properties, thereby enhancing the activity and stability of the catalyst.

[0083] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure, characterized in that, The Ni / TiO2-ZrO2 composite catalyst comprises a zirconium titanate (ZrTiO4) composite oxide support and a Ni metal active component supported on the support; wherein, the Ti element and Zr element in the zirconium titanate (ZrTiO4) composite oxide support are chemically bonded to form a zirconium titanate (ZrTiO4) structure with a heterojunction structure; the Ni / TiO2-ZrO2 composite catalyst is prepared by one-step reduction heat treatment.

2. The Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 1, characterized in that, The average particle size of the Ni metal is 11.30-12.49 nm, and the loading of the Ni metal is 19-21 wt% of the Ni / TiO2-ZrO2 composite catalyst.

3. The Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 1, characterized in that, The molar ratio of Ti to Zr in the Ni / TiO2-ZrO2 composite catalyst is 0.95:1.85-2.04; the BET specific surface area of ​​the Ni / TiO2-ZrO2 composite catalyst is 175-195 m². 2 / g.

4. The method for preparing the Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to any one of claims 1-3, characterized in that, Includes the following steps: S1. A composite precursor suspension is obtained by co-precipitating titanium source, zirconium source, nickel salt and sodium hydroxide. S2. The composite precursor suspension is subjected to aging, solid-liquid separation, washing, and drying to obtain the catalyst precursor; S3. The precursor is subjected to a one-step reduction heat treatment in a reducing atmosphere to obtain a one-step reduction heat treatment.

5. The method for preparing the Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 4, characterized in that, In step S1, the titanium source is at least one of TiO2, TiCl4, and TiOSO4; the zirconium source is at least one of zirconium oxychloride octahydrate, zirconium nitrate pentahydrate, zirconium sulfate, and basic zirconium carbonate; and the nickel source is at least one of nickel nitrate hexahydrate, nickel acetate tetrahydrate, nickel sulfate hexahydrate, and nickel chloride hexahydrate.

6. The method for preparing the Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 4, characterized in that, In step S1, the mass ratio of the titanium source, zirconium source, nickel salt and sodium hydroxide is 1:7.1-8.6:3.6-4.4:4.4-5.3; the pH value of the composite precursor suspension is 9.5-10.

5.

7. The method for preparing the Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 4, characterized in that, In step S2, the aging temperature is 75-85℃ and the time is 11.4-12.6h; the drying time is 11.4-12.6h.

8. The method for preparing the Ni / TiO2-ZrO2 composite catalyst with a heterojunction structure according to claim 4, characterized in that, In step S3, the reducing atmosphere is hydrogen gas with a flow rate of 76-84 mL / min; the one-step reduction heat treatment involves raising the temperature from room temperature to 570-630℃ at a rate of 4.75-5.25℃ / min, and reducing at this temperature for 0.95-1.05 h.

9. The application of the Ni / TiO2-ZrO2 composite catalyst with heterojunction structure according to any one of claims 1-3 or the Ni / TiO2-ZrO2 composite catalyst with heterojunction structure prepared by any one of claims 4-8 in the hydrodeoxygenation reaction of light phenolic components.

10. The application according to claim 9, characterized in that, The hydrodeoxygenation reaction is carried out at a temperature of 240-260℃ for 3-5 hours and a pressure of 1-2 MPa. The substrate of the light phenolic component includes one or more of phenol, guaiacol, and eugenol. The mass ratio of the substrate of the light phenolic component to the Ni / TiO2-ZrO2 composite catalyst is 5-15:2-10.

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