Reverse metal oxide-bimetallic alloy catalyst as well as preparation method and application thereof

Abstract

The invention discloses a reverse metal oxide-bimetallic alloy catalyst as well as a preparation method and application thereof. The method comprises the following steps: firstly synthesizing Sn / SiO2, then introducing Ni to prepare NiSn / SiO2, further introducing TiOx to obtain a Ti-NiSn / SiO2 bifunctional catalyst, and applying the prepared catalyst to hydrodeoxygenation of multiple biomass derived oxygen-containing compounds to prepare hydrocarbon fuels. According to the invention, a C-O bond is efficiently activated by using a bifunctional interface of the Ti-NiSn alloy; the non-oxyphilic Sn auxiliary agent inhibits carbon deposition, and meanwhile, the geometric electron modification effect of Sn on Ni can inhibit side reaction; the catalyst has the advantages of reducing the content of acid sites, inhibiting generation of carbon deposition in phenol condensation reaction and the like as well as fully reducing the content of TiOx through a reverse TiOx strategy, and shows excellent catalytic activity, hydrocarbon selectivity and stability in bio-oil platform molecule hydrodeoxygenation reaction.

Description

Technical Field

[0001] The present invention relates to the technical fields of chemical engineering and catalyst technology, and particularly relates to a reverse metal oxide-bimetallic alloy catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Lignocellulose is the most abundant non-edible biomass on the earth, mainly existing in plant cell walls and accounting for more than 90% of all plant biomass. Lignocellulose is mainly composed of cellulose (35 - 50%), hemicellulose (20 - 30%), and lignin (20 - 30%). The directional conversion of lignocellulose into fuels and high-value chemicals is of great significance. The conversion of lignocellulose into liquid fuels generally includes the following two stages according to different compositions. Among them, cellulose and hemicellulose are hydrolytically depolymerized into platform molecules 5-hydroxymethylfurfural or furfural; while lignin is pyrolyzed or catalytically depolymerized into bio-oil through rapid pyrolysis, and the main components are phenolic compounds such as guaiacol, anisole, and methylphenol. Subsequently, the platform molecules are converted into hydrocarbon compounds through catalytic hydrodeoxygenation and directly used as fuels or fuel additives. It is not difficult to see that the hydrodeoxygenation reaction is one of the key steps in the conversion of lignocellulose into hydrocarbon fuels, and the development of efficient hydrodeoxygenation catalysts has long been a research hotspot and focus in this field. Among compounds such as furfural, 5-hydroxymethylfurfural, and phenols, due to the highest dissociation energy of the phenolic hydroxyl C-O bond in phenolic compounds, the C-O bond breaking is the most difficult, and usually accompanied by side reactions such as benzene ring hydrogenation and C-C hydrogenolysis. Therefore, the regulation of the catalyst active sites is more demanding. Generally, efficient catalysts for phenolic hydrodeoxygenation are also applicable to the hydrodeoxygenation of platform molecules such as furfural and 5-hydroxymethylfurfural. In past explorations, bifunctional catalysts have been recognized as catalysts for efficiently activating the C-O bond. The bifunctional catalyst combines a hydrogenation metal component (such as Pt, Pd, Ni, etc.) with an oxygenophilic component (including oxygenophilic metals such as Mo, W, Re, etc. and oxygenophilic carriers such as TiO2, Nb2O5, ZrO2, etc.), and utilizes the advantages of activating H2 by the hydrogenation metal and activating C-O at the interface to achieve directional and efficient deoxygenation. By regulating the action mode of the bifunctional components, it is currently possible to achieve the highly active and highly selective conversion of molecules such as phenols or furfural into hydrocarbon fuels such as aromatics or methylfuran. However, due to the acidic characteristics of the oxygenophilic sites, the bifunctional catalyst still faces the serious problem of carbon deposition deactivation. Therefore, how to make full use of the advantages of the bifunctional catalyst in efficiently activating the C-O bond and weaken the problem of accelerated deactivation of its oxygenophilic sites has become the key to constructing a catalyst with high activity, high selectivity, and high stability. Summary of the Invention

[0003] In order to solve the problems in the prior art and address the challenge that it is difficult to balance the activity, selectivity, and stability of the hydrodeoxygenation reaction catalyst, the present invention provides an inexpensive reverse metal oxide (TiO x)-bimetallic alloy (NiSn) bifunctional catalyst (Ti-NiSn / SiO2) and its application in the hydrodeoxygenation of biomass-derived oxygenates. The Ti-NiSn alloy bifunctional interface is used to efficiently activate CO bonds; the non-oxophilic Sn additive inhibits carbon deposition, while the geometric electronic modification of Sn on Ni can inhibit the progress of side reactions; and the reverse TiO x Strategies to fully reduce TiO x The content of phenolic acid is reduced, thereby reducing the content of acidic sites and inhibiting the formation of carbon deposits during the condensation reaction of phenols. This effectively solves the technical problem of achieving both hydrodeoxygenation activity, selectivity and stability.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a method for preparing a reverse metal oxide-bimetallic alloy catalyst, comprising the following steps:

[0006] 1) dissolving tin chloride in water, adding dropwise to the silica support, grinding evenly, and standing overnight; the product after standing is dried and calcined to obtain a single metal Sn / SiO2 catalyst;

[0007] 2) dissolving nickel nitrate hexahydrate in water and adding the resultant solution dropwise to the Sn / SiO2 catalyst prepared in step 1), grinding the mixture evenly, and allowing the mixture to stand overnight; drying and calcining the resulting mixture to obtain a bimetallic NiSn / SiO2 catalyst;

[0008] 3) Tetrabutyl titanate was dissolved in ethanol, and the NiSn / SiO2 catalyst prepared in step 1) was added, and the mixture was stirred at 60° C. for 1 hour, followed by dropwise addition of water and continued stirring for 0.5 hour; the mixture was then filtered and dried to obtain a reverse Ti-NiSn / SiO2 catalyst;

[0009] 4) The Ti-NiSn / SiO2 catalyst prepared in step 3) is placed in a tubular furnace or a fixed bed reactor for reduction activation under the following conditions: heating to 350-500°C at a heating rate of 5-20°C / min in a hydrogen atmosphere and reducing for 1 hour.

[0010] In an optional embodiment, the tin chloride in step 1) is one or more of anhydrous tin dichloride, tin dichloride dihydrate, tin tetrachloride pentahydrate or dimethyltin dichloride.

[0011] In an optional embodiment, the mass ratio of tin chloride, water and silicon dioxide in step 1) is 0.1-0.5:10:5.

[0012] In an optional embodiment, the mass ratio of nickel nitrate hexahydrate, water, and Sn / SiO2 catalyst in step 2) is 0.3-1:5:5.

[0013] In an optional embodiment, the drying temperature in step 1) and step 2) is 100° C., and the drying time is 12 h.

[0014] In an optional embodiment, the calcination temperature in step 1) and step 2) is 400° C., the calcination time is 4 h, and the heating rate is 2° C. / min.

[0015] In an optional embodiment, the molar ratio of Ti to Ni in the tetrabutyl titanate and NiSn / SiO2 catalyst in step 3) is between 0.2 and 2.

[0016] In a second aspect, the present invention provides a Ti-NiSn / SiO2 bifunctional catalyst prepared by the above preparation method.

[0017] The Ti-NiSn / SiO2 bifunctional catalyst prepared by the present invention forms an alloy structure of NiSn after reduction, with an average particle size of 3-5nm; x It is mainly dispersed on the surface of NiSn alloy and mainly bonds with the Ni component in the alloy. It is also slightly dispersed in the SiO2 carrier.

[0018] In a third aspect, the present invention provides the above-mentioned Ti-NiSn / SiO2 bifunctional catalyst for application in the hydrodeoxygenation of biomass-derived oxygen-containing compounds such as lignin-derived m-cresol and anisole model phenolic compounds, hemicellulose-derived furfural, and cellulose-derived 5-hydroxymethylfurfural to prepare hydrocarbon compounds.

[0019] The reaction was carried out in a gas-solid phase fixed-bed reactor at atmospheric pressure, with sampling using a microsyringe pump and the reaction products quantitatively analyzed by online gas chromatography. The molar ratio of hydrogen to substrate (biomass-derived oxygenate) was 60, the reaction temperature was 250-400°C, the hydrogen pressure was 1 atm, and the reaction time was 0.01-4 hours.

[0020] The present invention discloses a method for preparing a reverse Ti-NiSn / SiO2 bifunctional catalyst, and the prepared catalyst is applied to the hydrodeoxygenation of various biomass-derived oxygen-containing compounds to prepare hydrocarbon fuels. x -NiSn alloy interface efficiently activates CO bonds; Sn additives inhibit carbon deposition, while Sn's geometric electronic modification of Ni inhibits side reactions; and reverse TiO x Strategies to fully reduce TiO x It has multiple advantages such as reducing the content of acidic sites, inhibiting the condensation reaction of phenols to generate carbon deposits, etc., and exhibits excellent catalytic activity, hydrocarbon selectivity and stability in the molecular hydrodeoxygenation reaction of bio-oil platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 are the XRD patterns after reduction of different catalysts.

[0022] Figure 2 are the HAADF image of the reduced Ti-NiSn / SiO2 catalyst and the EELS images of the Ni-L edge, Ti-L edge, and Sn-M edge.

[0023] Figure 3 are the CO adsorption spectra of Ni / SiO2, Ti-Ni / SiO2, NiSn / SiO2, and Ti-NiSn / SiO2 catalysts at 20 °C.

[0024] Figure 4 are the conversion rates and product distribution diagrams of m-cresol of Ni / SiO2, Ni / TiO2, NiSn / SiO2, and NiSn / TiO2 catalysts under the same conditions.

[0025] Figure 5 are the conversion rates and product distribution diagrams of m-cresol of Ni / SiO2, Ti-Ni / SiO2, NiSn / SiO2, and Ti-NiSn / SiO2 catalysts under the same conditions.

[0026] Figure 6 is the comparison of the stabilities of Ni / SiO2, Ni / TiO2, NiSn / SiO2, and NiSn / TiO2 catalysts.

[0027] Figure 7 is the comparison of the stabilities of TiNi / SiO2 and NiSn / TiO2 catalysts. Detailed implementation manners

[0028] To make the content of the present invention easy to understand, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners, but it should not be construed as a limitation to the present invention.

[0029] Example 1

[0030] Preparation of NiSn / SiO2 catalyst:

[0031] (1) Weigh 0.1838 g of stannous chloride dihydrate and dissolve it in 10 mL of water. Dropwise add it to 5 g of SiO2 support, grind evenly, and let it stand overnight at room temperature. Then dry it at 100 °C for 12 h, and further calcine it at 400 °C for 4 h in a muffle furnace under an air atmosphere with a heating rate of 2 °C / min to obtain Sn / SiO2.

[0032] (2) Weigh 0.5161 g of nickel nitrate hexahydrate and dissolve it in 5 mL of water. Dropwise add it to 5 g of the Sn / SiO₂ prepared in step (1), grind evenly, and let it stand overnight at room temperature. Then dry it in an oven at 100 °C for 12 h, and further calcine it in a muffle furnace under an air atmosphere at 400 °C for 4 h with a heating rate of 2 °C / min to obtain the NiSn / SiO₂ bimetallic catalyst.

[0033] To compare the influence of Sn, a Ni / SiO₂ catalyst was also prepared. The difference in its preparation method from that of the Sn / SiO₂ catalyst is that only nickel nitrate hexahydrate was used as the precursor.

[0034] To compare the influence of reverse loading of TiO x A NiSn bimetallic catalyst directly supported on the TiO₂ support (denoted as NiSn / TiO₂) was also prepared. The difference in its preparation method from that of the NiSn / SiO₂ catalyst is that TiO₂ was used as the support.

[0035] To compare the influence of Sn and reverse loading of TiO x A Ni monometallic catalyst directly supported on the TiO₂ support (denoted as Ni / TiO₂) was also prepared. The difference in its preparation method from that of the Ni / SiO₂ catalyst is that TiO₂ was used as the support.

[0036] All catalysts were activated in a tube furnace or a fixed-bed reactor before use. The activation conditions were: under a hydrogen atmosphere, heating to 400 °C at a heating rate of 10 °C / min and reducing for 1 h.

[0037] The XRD characterization results of the Ni / SiO₂, NiSn / SiO₂, NiSn / TiO₂, and Ni / TiO₂ catalysts obtained in this example are as Figure 1 shown. Ni / SiO₂ and Ni / TiO₂ showed characteristic diffraction peaks of metallic Ni. The characteristic diffraction peaks in NiSn / SiO₂ were significantly shifted compared to Ni, indicating the formation of the NiSn alloy. Due to the high dispersion of the metal, no diffraction signals of Ni or the NiSn alloy were detected in NiSn / TiO₂.

[0038] Example 2

[0039] Preparation of the Ti-NiSn / SiO₂ catalyst:

[0040] Weigh 3.5398 g of tetrabutyl titanate and dissolve it in 10 mL of ethanol. Add 2 g of the NiSn / SiO₂ catalyst prepared in Example 1 and stir at 60 °C for 1 h. Then dropwise add 2 mL of deionized water and continue stirring for 0.5 h. Then filter and dry at 100 °C for 12 h to obtain the reverse Ti-NiSn / SiO₂ catalyst.

[0041] To compare the influence of Sn, TiO x -Ni / SiO2 catalysts were prepared simultaneously. The preparation method of these catalysts is different from that of TiO x -NiSn / SiO2 catalysts in that Ni / SiO2 prepared in Example 1 was used as the initial catalyst.

[0042] All catalysts were reduced and activated in a tube furnace or a fixed-bed reactor under the following activation conditions: heated from room temperature to 400 °C at a heating rate of 10 °C / min in a hydrogen atmosphere and then reduced for 1 h.

[0043] The XRD characterization results of the Ti-NiSn / SiO2 and Ti-Ni / SiO2 catalysts obtained in this example are as Figure 1 shown. Compared with NiSn / SiO2 or Ni / SiO2 without TiO x , there were no obvious changes in their diffraction patterns, and no diffraction signals related to TiO x were detected, indicating that TiO x had a high dispersion in both NiSn / SiO2 and Ni / SiO2. In addition, it could be seen that the average size of the NiSn alloy was about 3 - 5 nm.

[0044] Figure 2 Figures are the HAADF image of the reduced Ti-NiSn / SiO2 catalyst and the EELS images of the Ni-L edge, Ti-L edge, and Sn-M edge. It can be seen that Ni and Sn were relatively uniformly dispersed in the NiSn alloy, Ti was mainly dispersed on the surface of the NiSn alloy and mainly formed bonds with Ni components in the alloy, and there was also a small amount of dispersion in the SiO2 support.

[0045] Example 3

[0046] This example demonstrates the in-situ CO adsorption infrared characterization of some catalysts in Example 1 and the catalysts in Example 2

[0047] The adsorption structure of CO on the catalysts in Example 2 was detected on an infrared spectrometer equipped with a diffuse reflection cell to explore the geometric and electronic modification effect of the Sn promoter on Ni, as well as the distribution of TiO x on Ni metal or NiSn alloy sites.

[0048] First, a certain amount of the catalyst was weighed and placed in an in-situ cell. It was heated to 400 °C in a H2 atmosphere and reduced for 1 h, and then cooled to 20 °C by circulating water. After stabilizing for 0.5 h, the background signal was recorded. Subsequently, H2 was switched to a CO / He mixed gas, and the CO adsorption signal was monitored in real time until the CO signal became stable. Further, it was switched to pure He purge to remove gaseous CO and physically adsorbed CO until the CO adsorption signal was stable. The results are as Figure 3As shown, by comparing the CO desorption stable signals of Ni / SiO2 and Ti-Ni / SiO2 catalysts, it can be seen that TiO x is mainly deposited on the Ni surface with low coordination, which is reflected in the obvious decrease of the CO signal of linear adsorption (~2077cm -1 ), while the Ni with high coordination is hardly affected, as shown by the fact that the CO signal of bridge adsorption (1940cm -1 ) remains basically unchanged. In addition, after the deposition of TiO x , the CO signal adsorbed on the Ni with low coordination undergoes a blue shift, and its wave number shifts from 2077cm -1 to 2075cm -1 , indicating that there is an electronic interaction between the deposited TiO x and Ni, and electrons transfer from TiO x to Ni. By comparing the NiSn / SiO2 catalyst and the Ni / SiO2 catalyst, it can be seen that the CO of bridge adsorption disappears after the introduction of Sn, indicating the geometric dispersion effect of Sn on Ni; at the same time, the CO signal of linear adsorption also undergoes an obvious blue shift, and its wave number shifts from 2077cm -1 on Ni / SiO2 to 2066cm -1 , indicating the electron-donating effect of Sn on Ni. By comparing NiSn / SiO2 and Ti-NiSn / SiO2, it can be found that the linear adsorption signal of CO is significantly weakened and its wave number undergoes a blue shift, proving the deposition of TiO x and its electron-donating effect on Ni. Through this characterization, the binding dispersion effect of Sn on Ni and their electronic interaction in the NiSn alloy are clarified. At the same time, it is also verified that TiO x is deposited on the surface of Ni particles and NiSn alloy, and there is an electronic interaction.

[0049] Example 4

[0050] Hydrodeoxygenation reaction of lignin-derived phenolic model compounds catalyzed by the catalyst prepared in Example 1

[0051] The hydrodeoxygenation reactions of lignin-derived phenolic model compounds m-cresol and anisole were carried out in an atmospheric-pressure gas-phase fixed-bed reactor. The catalyst was first reduced in hydrogen at 400 °C for 1 h under in-situ conditions and then adjusted to the reaction temperature of 250 - 400 °C. m-Cresol was injected into the reaction tube through a quantitative syringe and heated to 220 °C at the injection port to vaporize m-cresol. m-Cresol passed through the catalyst bed, and the products were analyzed by on-line gas chromatography. The molar ratio of hydrogen to m-cresol or anisole in the reaction was 60, and the reaction space time was 0.15 h. The reaction conversion rate and product distribution at a reaction temperature of 350 °C, a reaction hydrogen pressure of 1 atm, and a running time of 20 min are as Figure 4 shown.

[0052] Over the Ni / SiO2 catalyst, the conversion of m-cresol was 8.3%, yet the yield of the direct deoxygenation product toluene (the target product) was only 1.3%. The remaining products were by-products of C-C hydrogenolysis, such as methane, phenol, and benzene. In contrast, the Ni / TiO2 catalyst had a higher toluene selectivity. Although the m-cresol conversion decreased to 4.1%, the toluene yield increased to 2.5%. This was because the strong interaction between Ni and TiO2 caused partial reduction of TiO x to segregate to the Ni surface, partially covering the Ni sites, thus suppressing the structure-sensitive C-C hydrogenolysis side reaction. The Ni-TiO2 interface provided efficient deoxygenation sites, promoting the deoxygenation of m-cresol to toluene. The bimetallic NiSn / SiO2 catalyst exhibited a toluene selectivity of 98%. Its conversion was only 4.4%, but the toluene yield was as high as 4.3%. This was because the introduction of Sn formed NiSn alloy sites. The geometric dispersion effect of Sn on Ni could effectively inhibit the C-C hydrogenolysis side reaction, and the electronic modification effect of Sn on Ni was conducive to the adsorption and activation of phenolic hydroxyl groups on Ni, promoting the deoxygenation reaction to a certain extent. Different from the activity rules between Ni / SiO2 and Ni / TiO2, the activity of NiSn / TiO2 was much higher than that of NiSn / SiO2. The conversion of m-cresol reached 16.6%. The products were only toluene (yield 15.9%) and dimethylbiphenyl (yield 0.7%), and the total deoxygenation products reached 100%. This comparison indicated that the Sn promoter and TiO2 were both indispensable, and the synergistic effect among the three could greatly promote the highly selective deoxygenation of m-cresol to aromatics (toluene and dimethylbiphenyl).

[0053] Example 5

[0054] Using the catalyst prepared in Example 2 to catalyze the hydrodeoxygenation reaction of bio-oil platform molecules

[0055] The reaction evaluation operation was the same as in Example 4. The reaction results were as Figure 5 shown. Under the same reaction conditions, the reverse deposition of TiO x (Ti-Ni / SiO2) on the Ni / SiO2 catalyst would significantly reduce the catalytic activity. The conversion of m-cresol decreased from 8.3% to 4.9%, but the toluene yield increased from 1.3% to 2.3%. This rule was the same as the activity rules between Ni / SiO2 and Ni / TiO2, both due to the strong interaction between TiO x and Ni. And consistent with the rules between NiSn / SiO2 and NiSn / TiO2, the reverse deposition of TiO x(Ti-NiSn / SiO2) can also significantly promote the reaction, with the conversion rate of m-cresol increased to 15.8% and the selectivity of aromatic hydrocarbon products reaching 100%. This phenomenon further illustrates the synergistic effect of Sn, Ni, and TiO x among the three in the deoxygenation reaction of phenols, and none of them can be absent.

[0056] Example 6

[0057] Stability evaluation of the catalyst prepared in Example 1 for the hydrodeoxygenation of m-cresol

[0058] The operation of the stability evaluation is the same as that in Example 4. The reaction conditions are as follows: by adjusting the reaction space time, the initial conversion rate is about 95%, the reaction temperature is 350 °C, the reaction hydrogen pressure is 1 atm, and the running time is 350 min.

[0059] The results of the stability evaluation are as Figure 6 shown. The Ni / SiO2 catalyst deactivates rapidly with the increase of the running time. After running for 350 min, its conversion rate decreases from the initial 97% to 53%. The Ni / TiO2 catalyst deactivates even faster, and the conversion rate decreases from 93% to 4%. This is because the acidic sites of TiO2 accelerate the deactivation of the catalyst due to carbon deposition. In contrast, the introduction of the Sn promoter can greatly improve the stability. Among them, the NiSn catalyst supported on the inert SiO2 carrier (NiSn / SiO2) shows no obvious deactivation within 350 min of running time. Compared with Ni / TiO2, the conversion rate of NiSn / TiO2 only decreases from 95% to 57%. This comparison demonstrates the important role of the Sn promoter in improving the stability of the catalyst.

[0060] Example 7

[0061] Stability evaluation of the catalyst prepared in Example 2 for the hydrodeoxygenation of m-cresol

[0062] The operation of the stability evaluation is the same as that in Example 4. The reaction conditions are as follows: by adjusting the reaction space time, the initial conversion rate is about 95%, the reaction temperature is 350 °C, the reaction hydrogen pressure is 1 atm, and the running time is 350 min. The results of the stability evaluation are as Figure 7 shown. The reverse Ti-Ni / SiO2 catalyst deactivates extremely fast, and the conversion rate decreases from 96% to 12%, which is close to the deactivation rate of Ni / TiO2. The Ti-NiSn / SiO2 catalyst still maintains good stability, and the conversion rate only decreases from 91% to 80%. This indicates that the reverse Ti-NiSn / SiO2 catalyst not only has excellent activity and selectivity but also good stability. At the same time, the active components of this catalyst are cheap and easily available, showing good industrial application value.

[0063] Example 8

[0064] Example 1 Preparation of Catalysts and Performance Evaluation of the Hydrodeoxygenation Reaction of Furfural and 5-Hydroxymethylfurfural Derived from Cellulose and Hemicellulose

[0065] The reaction evaluation operation was the same as that in Example 4. The reaction conditions were as follows: the reaction temperature was 250 °C, the reaction hydrogen pressure was 1 atm, the reaction space time was 0.05 h, and the running time was 20 min. Similar to the reaction pattern of m-cresol, the NiSn / TiO2 catalyst showed the best activity and selectivity for the target product (2-methylfuran) among the four types of catalysts, indicating the efficient synergistic effect of Ni, Sn, and TiO x among the three.

[0066] Example 9

[0067] Example 2 Preparation of Catalysts and Stability Evaluation of the Hydrodeoxygenation of Furfural and 5-Hydroxymethylfurfural Derived from Cellulose and Hemicellulose

[0068] The reaction evaluation operation was the same as that in Example 4. The reaction conditions were as follows: the reaction temperature was 250 °C, the reaction space time was 0.05 h, and the running time was 20 min. Similar to the reaction pattern of m-cresol, the reverse Ti-NiSn / SiO2 catalyst had much higher activity and selectivity than the reverse Ti-Ni / SiO2, and its performance was close to that of NiSn / TiO2.

[0069] Example 10

[0070] Example 1 Preparation of Catalysts and Stability Evaluation of the Hydrodeoxygenation of Furfural and 5-Hydroxymethylfurfural Derived from Cellulose and Hemicellulose

[0071] The stability evaluation operation was the same as that in Example 4. The reaction conditions were as follows: the reaction temperature was 250 °C, the reaction hydrogen pressure was 1 atm, the initial conversion was adjusted to about 95% by adjusting the reaction space time, and the running time was 350 min. Similar to the reaction pattern of m-cresol, NiSn / SiO2 showed the best stability, followed by the NiSn / TiO2 catalyst. This indicates the important role of the Sn promoter in improving the stability of the catalyst.

[0072] Example 11

[0073] Example 2 Preparation of Catalysts and Stability Evaluation of the Hydrodeoxygenation of Furfural and 5-Hydroxymethylfurfural Derived from Cellulose and Hemicellulose

[0074] The reaction evaluation operation was the same as that in Example 4. The reaction conditions were as follows: the reaction temperature was 250 °C, the reaction hydrogen pressure was 1 atm, the initial conversion was adjusted to about 95% by adjusting the reaction space time, and the running time was 350 min. Similar to the reaction pattern of m-cresol, the reverse Ti-NiSn / SiO2 catalyst had much higher activity and selectivity than the reverse Ti-Ni / SiO2, and its performance was close to that of NiSn / TiO2.

[0075] As described above, it is only the specific implementation manner of the present invention. However, the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A method for preparing a reverse metal oxide-bimetallic alloy catalyst, characterized in that, It includes the following steps: 1) Dissolve stannous chloride in water, drop it into the silica support, grind evenly, and let it stand overnight; the product after standing is dried and calcined to obtain the monometallic Sn / SiO2 catalyst; 2) Dissolve nickel nitrate hexahydrate in water, drop it into the Sn / SiO2 catalyst prepared in step 1), grind evenly, and let it stand overnight; the product after standing is dried and calcined to obtain the bimetallic NiSn / SiO2 catalyst; 3) Dissolve tetrabutyl titanate in ethanol, add the NiSn / SiO2 catalyst prepared in step 1), stir at 60 °C for 1 hour, then dropwise add water and continue stirring for 0.5 hour; then filter and dry to obtain the inverse Ti-NiSn / SiO2 catalyst; 4) Place the Ti-NiSn / SiO2 catalyst prepared in step 3) in a tube furnace or a fixed-bed reactor for reduction activation, and the conditions are: in a hydrogen atmosphere, heat up to 350-500 °C at a heating rate of 5-20 °C / min and reduce for 1 h.

2. The preparation method of a reverse metal oxide-bimetallic alloy catalyst according to claim 1, characterized in that, The stannous chloride described in step 1) is one or more of anhydrous stannous chloride, stannous chloride dihydrate, stannic chloride pentahydrate, or dimethyldichlorotin; the mass ratio of the stannous chloride, water, and silica is 0.1-0.5:10:

5.

3. The preparation method of a reverse metal oxide-bimetallic alloy catalyst according to claim 1, characterized in that, The mass ratio of the nickel nitrate hexahydrate, water, and Sn / SiO2 catalyst described in step 2) is 0.3-1:5:

5.

4. The preparation method of a reverse metal oxide-bimetallic alloy catalyst according to claim 1, characterized in that, The drying temperature in steps 1) and 2) is 100 °C and the drying time is 12 h.

5. The preparation method of a reverse metal oxide-bimetallic alloy catalyst according to claim 1, characterized in that, The calcination temperature in steps 1) and 2) is 400 °C, the calcination time is 4 h, and the heating rate is 2 °C / min.

6. The preparation method of a reverse metal oxide-bimetallic alloy catalyst according to claim 1, characterized in that, The molar ratio of tetrabutyl titanate to Ti and Ni in the NiSn / SiO2 catalyst in step 3) is between 0.2 and 2.

7. The Ti-NiSn / SiO2 bifunctional catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the Ti-NiSn / SiO2 bifunctional catalyst according to claim 7 in the hydrodeoxygenation of biomass-derived oxygenates to prepare hydrocarbons.

9. The application according to claim 8, wherein The specific steps are that in a gas-solid phase atmospheric pressure reaction system, under a hydrogen atmosphere, the reaction hydrogen pressure is 1 atm, the reaction temperature is 250-400 °C, the reaction space time is 0.01-4 h, and the feed molar ratio of reaction hydrogen to reaction substrate is 60.

10. The application according to claim 8 or 9, characterized in that, The biomass-derived oxygenate is one of m-cresol, anisole, furfural, and 5-hydroxymethylfurfural.

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