Oxygen-vacancy-rich moo x / zro 2 catalyst for hydrodeoxygenation of biomass gas-solid system, and preparation method therefor and use thereof

Abstract

A method for preparing an oxygen-vacancy-rich MoOx / ZrO2 catalyst for hydrodeoxygenation of a biomass gas-solid system. The method comprises the following steps: (1) the preparation of oxygen-vacancy-rich ZrO2, involving: respectively dissolving zirconyl nitrate and ammonia water in deionized water, fully mixing same, aging, cooling, filtering, washing and drying same, and then calcining the resulting solid powder in an air atmosphere to obtain a ZrO2 solid; (2) adding ammonium molybdate tetrahydrate to deionized water to dissolve same, stirring same, dropwise adding same to the ZrO2 solid obtained in step (1), stirring same to achieve uniform loading, drying same to obtain a solid, grinding the solid, and calcining same in an air atmosphere to obtain an MoOx / ZrO2 powder; and (3) adding a Pt precursor to deionized water to dissolve same, dropwise adding same to the MoOx / ZrO2 powder obtained in step (2), stirring same to achieve uniform loading, then drying same to obtain a solid, grinding the solid, and calcining same in an air atmosphere to obtain a Pt-MoOx / ZrO2 catalyst.

Description

Biomass gas-solid system hydrodeoxygenation oxygen vacancy enrichment MoO x / ZrO2 catalyst and its preparation method and application Technical Field

[0001] The present invention belongs to the field of high-value utilization of biomass, and specifically relates to a Pt-doped oxygen-rich MoO x / ZrO2 catalyst, preparation method and application in gas-solid system hydrodeoxygenation of biomass-derived compounds. Background Art

[0002] Aromatic hydrocarbons (such as benzene, toluene, and xylene) are important raw materials for the chemical industry and are indispensable resources for industries such as plastics, aniline, synthetic resins, and pharmaceuticals. With the development of the refining and petroleum industries, aromatic hydrocarbon production has gradually shifted from coal tar to catalytic reforming and cracking of naphtha. However, fossil fuels are becoming increasingly depleted, and the massive consumption of fossil energy is leading to an increasingly severe greenhouse effect, placing tremendous pressure on the ecological environment. Biomass is a low-sulfur, low-nitrogen, carbon-neutral renewable energy source with abundant reserves, making it an ideal alternative to fossil energy. Therefore, the development of green, renewable biomass resources and the production of aromatic hydrocarbons through catalytic pyrolysis technology have attracted widespread attention.

[0003] Lignocellulosic biomass is the most abundant renewable hydrocarbon source, useful for the production of energy, fuels, and chemical products. As the most structurally complex component of lignocellulosic biomass, lignin is the only renewable energy source on Earth that can produce large quantities of aromatic compounds. Depolymerization yields phenolic compounds, which contain numerous oxygen-containing functional groups bound to the aromatic rings, making them difficult to remove. Catalytic hydrodeoxygenation (HDO) is a highly effective method for cleaving the CO bonds of lignin-derived phenols. Two parallel catalytic pathways exist for the HDO reaction: aromatic ring hydrogenation (HYD), which initially hydrogenates the aromatic rings, followed by further hydrogenation and dehydration. The other is direct CO bond cleavage (DDO), which cleaves the CO bond while leaving the aromatic rings intact. This cleavage method is most advantageous under high temperature and low pressure conditions, effectively reducing the possibility of over-hydrogenation of the aromatic rings and selectively producing the target aromatic hydrocarbons with minimal H₂ consumption. However, the high bond energy of the CO bond on the aromatic ring makes cleavage of this bond a significant challenge. Both pathways can further convert phenols into aromatics or cycloalkanes, with product selectivity varying significantly depending on temperature, pressure, and catalyst structure.

[0004] In view of the excellent low-temperature activity and hydrogenation performance of noble metals, noble metals are usually used to provide hydrogenation active sites for HDO reactions, and supports or introduced acidic oxides are used to provide acidic sites to catalyze dehydration reactions. However, noble metals have the disadvantage of easy agglomeration and deactivation, and aromatic ring hydrogenation is prone to occur under high pressure. In addition, their high cost and resource limitations cannot be ignored. MoO3 is an attractive catalyst that can be used for HDO of various biomass-derived oxygen-containing compounds, and metallic molybdenum is inexpensive. More importantly, MoO3 can selectively break CO bonds and has high activity and high aromatic selectivity at low H2 pressure. In the prior art, MoO3 is used to catalyze HDO of lignin-derived bio-oil at 450°C, with a deoxygenation degree of 52% and an aromatic hydrocarbon-rich organic liquid yield of about 16.2wt%. Part of Mo 6+ Will be reduced to Mo under the action of H2 5+ , the two metals Mo with different valences produce a synergistic effect to achieve HDO reaction. However, in the HDO process, Mo 5+ Species are prone to overreduction to Mo 4+ , causing catalyst deactivation. At high temperatures, coke easily forms on the catalyst surface, leading to deactivation. Simultaneously, the catalyst itself can also sinter and deactivate due to structural changes. Therefore, there is an urgent need to develop a catalyst with excellent activity, selectivity, and stability to achieve efficient hydrodeoxygenation of lignin-derived compounds to aromatics under mild conditions.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a biomass gas-solid system hydrodeoxygenation oxygen vacancy enriched MoO x / ZrO2 catalyst and its preparation method and application. The catalyst prepared by this method has high catalytic activity and good stability, and can solve the current problem of low yield of target product aromatics by hydrodeoxygenation of lignin and its derived phenolic compounds.

[0007] The purpose of the present invention can be achieved by the following technical solutions: a biomass gas-solid system hydrogenation deoxygenation oxygen vacancy enriched MoO x The preparation method of the ZrO2 catalyst comprises the following steps:

[0008] (1) Preparation of oxygen-vacancy-rich ZrO2: Zirconium oxide dinitrate and ammonia water were dissolved in deionized water, mixed, aged, cooled, filtered, washed, and dried, and the resulting solid powder was calcined in an air atmosphere to obtain ZrO2 solid;

[0009] (2) Add ammonium molybdate tetrahydrate into deionized water and dissolve it, stir it, and add it dropwise to the ZrO2 solid obtained in step (1), stir it to make the load uniform, dry it to obtain a solid, grind it, and calcine it in air atmosphere to obtain MoO x / ZrO2 powder;

[0010] (3) Add the Pt precursor into deionized water to dissolve it, and add the MoO obtained in step (2) dropwise. x / ZrO2 powder, stirred to make the load uniform, dried to obtain a solid, ground, and calcined in air atmosphere to obtain Pt-MoO x / ZrO2 catalyst.

[0011] Furthermore, in step (1), the mixture is aged at a temperature of 80-120° C. for a time of 12-36 hours.

[0012] Furthermore, in step (1), the calcination conditions are: temperature of 300-500°C, heating rate of 5-8°C / min, and holding time of 2-4h;

[0013] In step (2), the calcination conditions are: temperature of 450-800°C, heating rate of 5-8°C / min, and holding time of 2-4h;

[0014] In step (3), the calcination conditions are: temperature of 450-800° C., heating rate of 5-8° C. / min, and holding time of 2-4 h.

[0015] Furthermore, in step (2), the mass ratio of ammonium molybdate tetrahydrate to ZrO2 is 1 / 15 to 1 / 5.

[0016] Furthermore, in step (3), the Pt precursor includes chloroplatinic acid hexahydrate or platinum nitrate.

[0017] Furthermore, the obtained Pt-MoO x The loading amount of precious metal Pt in the ZrO2 / ZrO2 catalyst is 0.1-1%.

[0018] The present invention also provides a biomass gas-solid system hydrogenation deoxygenation oxygen vacancy-enriched MoO prepared by the method. x / ZrO2 catalyst, the catalyst is Pt-MoO x / ZrO2, wherein the loading amount of precious metal Pt is 0.1-1%, and x is 2-3.

[0019] The present invention also provides a biomass gas-solid system hydrodeoxygenation oxygen vacancy enriched MoO x / ZrO2 catalyst, the Pt-MoO x / ZrO2 catalyst is used in the hydrodeoxygenation reaction of lignin and its derived phenolic compounds.

[0020] Furthermore, the hydrodeoxygenation reaction is carried out in a fixed bed at a reaction temperature of 350-450°C.

[0021] Furthermore, the hydrodeoxygenation reaction is carried out under normal pressure, thereby avoiding the use of high-pressure hydrogen in traditional hydrogenation reactions and reducing hydrogen consumption.

[0022] The hydrodeoxygenation reaction involves grinding and mixing the catalyst and silica at a mass ratio of 5:30:200, placing the mixture between two layers of quartz wool, and placing it in the center of a fixed bed. Before the reaction, the reactor is first purged of any residual air with nitrogen. The temperature is then raised to 350-450°C in an hydrogen atmosphere at a rate of 5-15°C / min and maintained at this temperature for 20-40 minutes to fully activate the catalyst. Lignin or its derivative phenolic compounds are introduced into the reactor via a syringe pump and mixed with hydrogen at the reactor inlet. The reactant flow rate is adjusted to achieve a specific mass space velocity (WHSV). A two-stage condenser is connected to the reactor tail, and the gaseous products are collected using a gas bag for qualitative and quantitative analysis using GC / MS and GC-FID.

[0023] Bifunctional catalysts have shown high activity and are receiving increasing attention. Metals (Pt, Pd, Ru, etc.) adsorb and activate H2 molecules, and the activated proton hydrogen overflows to the support surface, providing additional active sites for the hydrogenation reaction. It has been confirmed that the interaction between Pt and different oxides significantly affects the selectivity of the target product. Reducible metal oxides significantly increase the adsorption capacity of -OH groups on the catalyst through oxygen vacancies, which is conducive to direct deoxygenation under high temperature and low pressure. The close combination between the active sites affects the selectivity of aromatic hydrocarbons. Compared with the prior art, the present invention has the following beneficial effects:

[0024] The catalyst prepared by the method of the present invention can make the hydrogen-activated metal Pt highly dispersed on the carrier surface, thereby improving the hydrogenation deoxygenation activity; at the same time, the oxygen-vacancy-rich ZrO2 carrier can absorb the active hydrogen formed by hydrogen overflow, promote catalytic activity, improve stability, and effectively inhibit the excessive reduction of Mo species.

[0025] Hydrogen activated metal-doped MoO x The catalyst significantly enhances stability and catalytic activity. The high surface area of ​​the support greatly improves the dispersion of the active molybdenum species and regulates the geometric configuration and electronic structure. Oxygen-rich vacancies effectively inhibit over-reduction of the Mo species, which can lead to catalyst deactivation, further improving catalyst stability.

[0026] When biomass-derived compounds are hydrodeoxygenated, selective breaking of CO bonds can be achieved at normal pressure, with conversion and deoxygenation rates reaching 100% and 97.5%, respectively, and the selectivity of target aromatic products benzene, toluene, and xylene (BTX) reaching up to 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is an XPS characterization diagram of the catalysts of Examples 1 and 2 of the present invention and Comparative Examples 1 and 2;

[0028] FIG2 is an EPR characterization diagram of the oxygen vacancy-rich ZrO2 solid catalyst prepared by the present invention. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] The present invention provides a biomass gas-solid system hydrodeoxygenation oxygen vacancy enriched MoO x The present invention is further described by the following examples. The examples are only used to illustrate the present invention and are not used to limit the present invention.

[0031] The various raw materials used in the present invention are all commonly available commercial products in the field, for example:

[0032] The zirconium dinitrate used in the present invention has a CAS number of 14985-18-3, a molecular formula of H2N2O8Zr, and a molecular weight of 249.25.

[0033] Example 1:

[0034] Take 11.35g of zirconium dinitrate and dissolve it in deionized water to make 61.4mL solution and stir for 2h to fully dissolve it; take 9.72mL of concentrated ammonia water and dissolve it in deionized water to make 180mL of dilute ammonia solution; add the zirconium dinitrate solution dropwise into the dilute ammonia water, stir it with a magnetic stirrer for 2h to fully mix it, and then place it in a 100℃ oven for aging for 24h; after the mixture solution is cooled to room temperature, it is filtered through a vacuum pump and washed with deionized water until it is neutral, and then placed in a 100℃ oven to dry for 12h; the dried solid is placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 400℃ at a rate of 5℃ / min, and maintained at this temperature for 4h. The resulting solid powder is ZrO2.

[0035] 0.55 g of ammonium molybdate tetrahydrate was dissolved in 6 mL of deionized water and stirred for 2 h to fully dissolve, then added dropwise to 4.5 g of ZrO2 and stirred for 8 h to uniformly load the solution. The solution was then placed in a 100 °C oven and dried for 12 h. The dried solid was placed in a mortar and fully ground into powder. The solid was then placed in a muffle furnace and rapidly heated to 550 °C at a rate of 5 °C / min and maintained at this temperature for 3 h. The resulting solid powder was recorded as MoO x / ZrO2.

[0036] Dissolve chloroplatinic acid hexahydrate in deionized water to prepare 5 mL of solution. Take out a certain volume of solution so that the Pt loading is 0.3%, and add the MoO prepared by the above preparation method dropwise. x / ZrO2 catalyst; stirred by a magnetic stirrer for 8 hours to make the loading uniform, and then placed in a 100℃ oven to dry for 12 hours; the dried solid was placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 550℃ at a rate of 5℃ / min and maintained at this temperature for 3 hours to prepare 0.3% Pt-MoO x / ZrO2 catalyst.

[0037] The catalyst performance test was carried out by the hydrodeoxygenation reaction of guaiacol in a fixed bed reactor. 30 mg of catalyst was weighed and mixed with 200 mg of silica, then ground and mixed evenly, placed between two layers of quartz wool, and placed in the middle of the fixed bed. Before the reaction, the reactor was first purged of residual air at 80 mL / min N2, and then heated to 400 °C at a rate of 10 °C / min in a 60 mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30 minutes to fully activate the catalyst. Guaiacol was fed into the reactor through an injection pump, and the mass space velocity of guaiacol feed rate relative to the amount of catalyst was 2.26 h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0038] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 100%, the deoxygenation rate was 97.5%, the selectivity of BTX was 95%, and the selectivity of phenolic compounds was 5%.

[0039] Example 2:

[0040] Effect of different Pt loadings on the hydrodeoxygenation of lignin-derived phenolic compounds. Chloroplatinic acid hexahydrate was dissolved in deionized water to prepare a 5 mL solution. A certain volume of solution was taken out to make the Pt loading amount 0.1%, and the MoO prepared by the above preparation method was added dropwise. x / ZrO2 catalyst; stirred by a magnetic stirrer for 8 hours to make the loading uniform, and then placed in a 100℃ oven to dry for 12 hours; the dried solid was placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 550℃ at a rate of 5℃ / min and maintained at this temperature for 3 hours to prepare 0.1% Pt-MoO x / ZrO2 catalyst.

[0041] The catalyst performance test method was the same as in Example 1. The hydrodeoxygenation product was qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the guaiacol conversion rate was 93%, the deoxygenation rate was 46.5%, the selectivity for phenol was 63%, and the selectivity for cresol was 37%.

[0042] Example 3:

[0043] Effect of different Pt loadings on the hydrodeoxygenation of lignin-derived phenolic compounds. Chloroplatinic acid hexahydrate was dissolved in deionized water to prepare a 5 mL solution. A certain volume of solution was taken out to make the Pt loading amount 0.5%, and the MoO prepared by the above preparation method was added dropwise. x / ZrO2 catalyst; stirred by a magnetic stirrer for 8 hours to make the loading uniform, and then placed in a 100℃ oven to dry for 12 hours; the dried solid was placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 550℃ at a rate of 5℃ / min and maintained at this temperature for 3 hours to prepare 0.5% Pt-MoO x / ZrO2 catalyst.

[0044] The catalyst performance test method was the same as in Example 1. The hydrodeoxygenation product was qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the guaiacol conversion rate was 100%, the deoxygenation rate was 96%, the BTX selectivity was 92%, and the selectivity for phenolic compounds was 8%.

[0045] Example 4:

[0046] Effect of different Pt loadings on the hydrodeoxygenation of lignin-derived phenolic compounds. Chloroplatinic acid hexahydrate was dissolved in deionized water to prepare a 5 mL solution. A certain volume of solution was taken out to make the Pt loading amount 1%, and the MoO prepared by the above preparation method was added dropwise. x / ZrO2 catalyst; stirred by a magnetic stirrer for 8 hours to make the loading uniform, and then placed in a 100℃ oven to dry for 12 hours; the dried solid was placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 550℃ at a rate of 5℃ / min and maintained at this temperature for 3 hours to prepare 1% Pt-MoO x / ZrO2 catalyst.

[0047] The catalyst performance test method was the same as in Example 1. The hydrodeoxygenation product was qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the guaiacol conversion rate was 100%, the deoxygenation rate was 79%, the BTX selectivity was 58%, and the selectivity for phenolic compounds was 42%.

[0048] Example 5:

[0049] Effect of different reaction temperatures on the hydrodeoxygenation of lignin-derived phenolic compounds. The catalyst preparation method is the same as in Example 1, 0.3% Pt-MoO x / ZrO2 catalyst performance test is carried out by hydrogenation deoxygenation reaction of guaiacol in a fixed bed reactor. 30mg of catalyst is weighed and mixed with 200mg of silica, then ground and mixed evenly, placed between two layers of quartz wool, and placed in the middle of the fixed bed. Before the reaction, the reactor is first purged of residual air at 80mL / min N2, and then heated to 350℃ at a rate of 10℃ / min in a 60mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30min to fully activate the catalyst. Guaiacol is fed into the reactor through an injection pump, and the mass space velocity of guaiacol feed rate relative to the amount of catalyst is 2.26h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0050] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 96%, the deoxygenation rate was 92%, the selectivity of BTX was 39%, and the selectivity of phenolic compounds was 61%.

[0051] Example 6:

[0052] Effect of different reaction temperatures on the hydrodeoxygenation of lignin-derived phenolic compounds. The catalyst preparation method is the same as in Example 1, 0.3% Pt-MoO x / ZrO2 catalyst performance test is carried out by hydrogenation deoxygenation reaction of guaiacol in a fixed bed reactor. Weigh 30mg of catalyst and 200mg of silica, grind and mix them evenly, put them between two layers of quartz wool, and place them in the middle of the fixed bed. Before the reaction, the reactor is first purged of residual air with 80mL / min N2, and then heated to 450℃ at a rate of 10℃ / min in a 60mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30min to fully activate the catalyst. Guaiacol is fed into the reactor through an injection pump, and the mass space velocity of guaiacol feed rate relative to the amount of catalyst is 2.26h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0053] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 100%, the deoxygenation rate was 95%, the selectivity of BTX was 90%, and the selectivity of phenolic compounds was 10%.

[0054] Example 7:

[0055] Effect of different mass space velocities on the hydrodeoxygenation of lignin-derived phenolic compounds. The catalyst preparation method is the same as that in Example 1, with 0.3% Pt-MoO x / ZrO2 catalyst performance test is carried out by hydrogenation deoxygenation reaction of guaiacol in a fixed bed reactor. 5 mg of catalyst is weighed and ground with 200 mg of silica, mixed evenly, placed between two layers of quartz wool, and placed in the middle of the fixed bed. Before the reaction, the reactor is first purged of residual air with 80 mL / min N2, and then heated to 400 ° C at a rate of 10 ° C / min in a 60 mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30 minutes to fully activate the catalyst. Guaiacol is fed into the reactor through an injection pump, and the mass space velocity of guaiacol feed rate relative to the amount of catalyst is 13.56 h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0056] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 89%, the deoxygenation rate was 45%, and the selectivity of phenol was 100%.

[0057] Example 8:

[0058] Effect of different mass space velocities on the hydrodeoxygenation of lignin-derived phenolic compounds. The catalyst preparation method is the same as in Example 1, and the catalyst performance test is to carry out the hydrodeoxygenation reaction of guaiacol in a fixed bed reactor. Weigh 20 mg of catalyst and 200 mg of silica, grind and mix evenly, put it between two layers of quartz wool, and place it in the middle of the fixed bed. Before the reaction, the reactor is first purged of residual air at 80 mL / min N2, and then heated to 400 ° C at a rate of 10 ° C / min in a 60 mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30 min to fully activate the catalyst. Guaiacol is fed into the reactor by an injection pump, and the mass space velocity of the guaiacol feed rate relative to the amount of catalyst is 3.39 h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0059] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 97%, the deoxygenation rate was 54%, the selectivity of BTX was 9%, and the selectivity of phenolic compounds was 93%.

[0060] Comparative Example 1:

[0061] 0.55 g of ammonium molybdate tetrahydrate was dissolved in 6 mL of deionized water and stirred for 2 h to fully dissolve, then added dropwise to 4.5 g of commercial ZrO2 and stirred for 8 h to uniformly load the solution, and then placed in a 100 ° C oven to dry for 12 h; the dried solid was placed in a mortar and fully ground into powder, then placed in a muffle furnace and rapidly heated to 550 ° C at a rate of 5 ° C / min, and maintained at this temperature for 3 h to prepare MoO x / ZrO2 Com. catalyst.

[0062] The catalyst performance test was carried out by the hydrodeoxygenation reaction of guaiacol in a fixed bed reactor. 30 mg of catalyst and 200 mg of silica were ground and mixed evenly, placed between two layers of quartz wool, and placed in the middle of the fixed bed. Before the reaction, the reactor was first purged of residual air at 80 mL / min N2, and then heated to 400 °C at a rate of 10 °C / min in a 60 mL / min atmospheric pressure H2 atmosphere, and maintained at this temperature for 30 minutes to fully activate the catalyst. Guaiacol was fed into the reactor by an injection pump, and the mass space velocity of guaiacol feed rate relative to the amount of catalyst was 2.26 h -1 The liquid product was collected through a condensation system in an ice-water bath, and the gaseous product was collected through an air bag.

[0063] The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the conversion of guaiacol was 8%, the deoxygenation rate was 4%, and the selectivity of phenolic compounds was 100%.

[0064] Comparative Example 2:

[0065] Take 11.35g of zirconium dinitrate and dissolve it in deionized water to make 61.4mL solution and stir for 2h to fully dissolve it; take 9.72mL of concentrated ammonia water and dissolve it in deionized water to make 180mL of dilute ammonia solution; add the zirconium dinitrate solution dropwise into the dilute ammonia water, stir it with a magnetic stirrer for 2h to fully mix it, and then place it in a 100℃ oven for aging for 24h; after the mixture solution is cooled to room temperature, it is filtered through a vacuum pump and washed with deionized water until it is neutral, and then placed in a 100℃ oven to dry for 12h; the dried solid is placed in a mortar and fully ground into powder, and then placed in a muffle furnace and rapidly heated to 400℃ at a rate of 5℃ / min, and maintained at this temperature for 4h. The resulting solid powder is ZrO2.

[0066] 0.55 g of ammonium molybdate tetrahydrate was dissolved in 6 mL of deionized water and stirred for 2 h to fully dissolve, then added dropwise to 4.5 g of ZrO2 and stirred for 8 h to uniformly load the solution, and then placed in a 100 °C oven to dry for 12 h; the dried solid was placed in a mortar and fully ground into powder, then placed in a muffle furnace and rapidly heated to 550 °C at a rate of 5 °C / min and maintained at this temperature for 3 h to prepare MoO x / ZrO2 catalyst.

[0067] The catalyst performance test method was the same as that of Comparative Example 1. The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the guaiacol conversion rate was 73%, the deoxygenation rate was 36.5%, the selectivity for phenol was 58%, and the selectivity for cresol was 42%.

[0068] Comparative Example 3:

[0069] MoO x / ZrO2 Com. The catalyst preparation method is the same as that of Comparative Example 1. The Pt precursor is dissolved in deionized water to prepare a 5 ml solution. A certain volume of the solution is taken out to obtain a Pt loading of 0.3%, and then added dropwise to the solid powder prepared above. The solution is stirred for 8 hours using a magnetic stirrer to ensure uniform loading, and then dried in a 100°C oven for 12 hours. The dried solid is then thoroughly ground into a powder in a mortar, and then rapidly heated to 550°C in a muffle furnace at a rate of 5°C / min and maintained at this temperature for 3 hours to prepare 0.3% Pt-MoO x / ZrO2 Com. catalyst.

[0070] The catalyst performance test method was the same as that of Comparative Example 1. The hydrodeoxygenation products were qualitatively and quantitatively analyzed by GC / MS and GC-FID. The results showed that the guaiacol conversion rate was 85%, the deoxygenation rate was 64%, the BTX selectivity was 35%, and the selectivity for phenolic compounds was 65%.

[0071] The difference between Example 1 and Comparative Example 2 is that Example 1 is loaded with Pt, while Comparative Example 2 is not loaded with Pt. It can be seen that although the catalyst prepared in Comparative Example 2 has certain activity and selectivity, the effect is far inferior to the catalyst prepared in Example 1 which is loaded with Pt;

[0072] In Examples 1-4, the Pt content gradually increases. It can be seen that too high a Pt loading will cause over-reduction of the catalyst, resulting in a weakening of the catalyst's hydrodeoxygenation activity. The catalyst with a 0.3% loading has the highest deoxygenation rate and BTX selectivity.

[0073] Comparing Example 1 with Examples 5 and 6, it can be seen that at a lower reaction temperature, guaiacol was not completely converted and the BTX selectivity was significantly reduced. While increasing the reaction temperature achieved a conversion rate of 100%, the catalytic activity and selectivity were slightly lower than those of Example 1.

[0074] Comparing Example 1 with Examples 7 and 8, it can be seen that different mass space velocities have a significant impact on catalytic activity and product selectivity. Reducing the catalyst dosage results in incomplete conversion of guaiacol, significantly reducing the deoxygenation rate and selectivity of the target product BTX.

[0075] Comparing Comparative Example 1 with Comparative Example 2, it can be seen that the MoO x The conversion rate of guaiacol by the catalyst is only 8%, which is much lower than that of MoO2 when the oxygen vacancy-rich ZrO2 is used as the support. x / 73% conversion of ZrO2.

[0076] Comparing Example 1 with Comparative Example 3, it can be seen that compared with the catalyst prepared using commercial ZrO2, the self-made oxygen-rich vacancy type 0.3% Pt-MoO x / ZrO2 catalyst has high conversion rate and deoxygenation rate, and selectively regulates the target product BTX.

[0077] Figure 1 shows XPS characterizations of the catalysts prepared in Example 1 and Comparative Examples 1, 2, and 3 of the present invention. In Figure 1, Mo-Zr Com. represents the XPS characterization of the catalyst prepared in Comparative Example 1; Mo-Zr represents the XPS characterization of the catalyst prepared in Comparative Example 2; 0.3Pt-Mo-Zr Com represents the XPS characterization of the catalyst prepared in Comparative Example 3; and 0.3Pt-Mo-Zr represents the XPS characterization of the catalyst prepared in Example 1. The figures show that the oxygen-vacancy-rich catalyst prepared in the present invention effectively suppresses the overreduction of Mo species, facilitates the adsorption of oxygen-containing groups by the catalyst, and effectively improves the HDO activity and stability of the catalyst.

[0078] Figure 2 is an EPR characterization graph of the oxygen-vacancy-rich ZrO2 solid catalyst prepared by the present invention. ZrO2 is the EPR characterization graph of the solid powder ZrO2 prepared in Example 1, 0.3Pt-Mo-Zr is the EPR characterization graph of the catalyst prepared in Example 1, and 0.3Pt-Mo-Zr Com is the EPR characterization graph of the catalyst prepared in Comparative Example 3. It can be seen from the graph that the oxygen-vacancy-rich ZrO2 prepared by the present invention has abundant oxygen vacancies compared to commercial ZrO2.

[0079] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the technical scope of the present invention. Any minor modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention are also included in the patent protection scope of the present invention.

Claims

1. A preparation method of a hydrogenation and deoxygenation MoO x / ZrO2 catalyst with oxygen vacancies in a biomass gas-solid system, characterized in that, The steps include: (1) Preparation of oxygen-vacancy-rich ZrO2: Zirconium oxide dinitrate and ammonia water were dissolved in deionized water, mixed, aged, cooled, filtered, washed, and dried, and the resulting solid powder was calcined in an air atmosphere to obtain ZrO2 solid; (2) Dissolve ammonium molybdate tetrahydrate in deionized water, stir, and gradually add it dropwise to the ZrO2 solid obtained in step (1). Stir to make the loading uniform, dry to obtain a solid, grind it, and calcine it in an air atmosphere to obtain MoO x / ZrO2 powder; (3) Dissolve the Pt precursor in deionized water and add it dropwise to the MoO x / ZrO2 powder obtained in step (2), stir to make the loading uniform, dry to obtain a solid, grind it, and calcine it in an air atmosphere to obtain the Pt-MoO x / ZrO2 catalyst.

2. Preparation method of a biomass gas-solid system hydrodeoxygenation oxygen vacancy-rich MoO x / ZrO2 catalyst, characterized in that, In step (1), the mixture is aged at a temperature of 80-120° C. for 12-36 hours.

3. Preparation method of a biomass gas-solid system hydrodeoxygenation oxygen vacancy-rich MoO x / ZrO2 catalyst, characterized in that, In step (1), the calcination conditions are: temperature of 300-500°C, heating rate of 5-8°C / min, and holding time of 2-4h; In step (2), the calcination conditions are: temperature of 450-800°C, heating rate of 5-8°C / min, and holding time of 2-4h; In step (3), the calcination conditions are: temperature of 450-800° C., heating rate of 5-8° C. / min, and holding time of 2-4 h.

4. A preparation method of a biomass gas-solid system hydrodeoxygenation oxygen-rich vacancy MoO x / ZrO2 catalyst, characterized in that, In step (2), the mass ratio of ammonium molybdate tetrahydrate to ZrO2 is 1 / 15 to 1 / 5.

5. A preparation method of a biomass gas-solid system hydrodeoxygenation oxygen vacancy-rich MoO x / ZrO2 catalyst, characterized in that, In step (3), the Pt precursor includes chloroplatinic acid hexahydrate or platinum nitrate.

6. A biomass gas-solid system hydrodeoxygenation oxygen vacancy-rich MoO x / ZrO2 catalyst prepared by the method according to any one of claims 1-5, characterized in that, The catalyst is Pt-MoO x / ZrO2, where the loading of the noble metal Pt is 0.1-1%, and x is 2-3.

7. Application of a hydrogenation and deoxygenation and oxygen vacancy-rich MoO x / ZrO2 catalyst as described in claim 6, characterized in that Apply the described Pt-MoO x / ZrO2 catalyst to the hydrodeoxygenation reaction of lignin and its derived phenolic compounds.

8. Use of a hydrogenation and deoxygenation rich oxygen vacancy MoO x / ZrO2 catalyst according to claim 7, characterized in that, The hydrodeoxygenation reaction is carried out in a fixed bed at a reaction temperature of 350-450°C.

9. Use of a bio-based gas-solid system hydrodeoxygenation oxygen-vacancy-rich MoO x / ZrO2 catalyst, characterized in that, The hydrodeoxygenation reaction is carried out under normal pressure.

10. Use of a biomass gas-solid system hydrodeoxygenation oxygen vacancy-rich MoO x / ZrO2 catalyst, characterized in that, Before use, the catalyst is heated to 350-450° C. at a heating rate of 5-15° C. / min in a H2 atmosphere and maintained at the temperature for 20-40 minutes to fully activate the catalyst.

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