阅读说明：本技术 一种二硫化钼-铌酸催化剂在苯甲醚加氢脱氧中的应用 (Application of molybdenum disulfide-niobic acid catalyst in anisole hydrodeoxygenation ) 是由 宋春风 王振娇 刁新勇 李婷婷 刘庆岭 纪娜 于 2019-09-11 设计创作，主要内容包括：本发明涉及一种二硫化钼-铌酸催化剂在苯甲醚加氢脱氧中的应用；称取催化剂加入到间歇式高压反应釜中,加入苯甲醚溶液,装好反应釜；反应在氢气的初始压力为1-6MPa,反应温度为150-300℃,反应时间为1-5h,搅拌转数为1000r/min的条件下进行,反应结束后待其自然冷却将样品取出,运用气相色谱进行检测。本发明中反应溶剂为常用有机溶剂,无污染,具有环境友好性,并且反应过程不使用任何的酸、碱性物质。本发明中木质素单体苯甲醚的转化率高,且产物中酚类为主要产物,催化剂对于此反应的选择性强,主产物为具有高附加值的化学品,在工业上广泛应用,所以本发明中催化剂具有良好的工业应用前景。(The invention relates to an application of a molybdenum disulfide-niobic acid catalyst in anisole hydrodeoxygenation; weighing a catalyst, adding the catalyst into an intermittent high-pressure reaction kettle, adding an anisole solution, and filling the reaction kettle; the reaction is carried out under the conditions that the initial pressure of hydrogen is 1-6MPa, the reaction temperature is 150-. The reaction solvent is a common organic solvent, is pollution-free and environment-friendly, and does not use any acid or alkaline substances in the reaction process. The conversion rate of the lignin monomer anisole is high, phenols in the product are main products, the catalyst has strong selectivity for the reaction, and the main products are chemicals with high added values and are widely applied in industry, so the catalyst has good industrial application prospect.)

1. The application of the molybdenum disulfide-niobic acid catalyst in anisole hydrodeoxygenation is characterized by comprising the following steps of:

1) weighing a molybdenum disulfide-niobic acid catalyst, adding the molybdenum disulfide-niobic acid catalyst into an intermittent high-pressure reaction kettle, adding an anisole solution, and filling the reaction kettle;

2) the reaction is carried out under the conditions that the initial pressure of hydrogen is 1-6MPa, the reaction temperature is 150-.

2. The method as set forth in claim 1, characterized in that the internal standard substance in the anisole solution is n-dodecane, and the solvent used in the anisole solution is one of methylcyclohexane, n-hexane, decalin, methanol, ethanol, or a mixture of the above solvents in any proportion.

3. The process as claimed in claim 1, wherein the mass ratio of anisole to catalyst is from 1:1 to 10: 1.

4. The method as set forth in claim 1, wherein the concentration of anisole solution is in the range of 0.05 to 0.15 mol/L.

5. The method as set forth in claim 1, characterized in that the molybdenum disulfide-niobic acid catalyst has the formula A_xB_yS_z-H₄Nb₂O₇Wherein A, B is one or two of different metal elements of Co, Mo, Ni, Cu, Zn and Fe. Wherein x is more than 0 and less than 10, y is more than or equal to 0 and less than 10, and z is more than 0 and less than 10, and the specific numerical value is generally determined according to the valence state of the compound.

Technical Field

The invention belongs to the technical field of synthesis and application of novel catalytic materials, and particularly relates to application of a molybdenum disulfide-niobic acid catalyst in preparation of high value-added fine chemicals through catalytic conversion of biomass.

Background

The rapid increase in global energy demand, the ever-decreasing reserves of fossil fuels, and the serious environmental problems worldwide have prompted us to search for other renewable energy sources. Among various renewable energy sources, the woody biomass has rich content, wide sources, low price and easy obtainment, meets the requirement of sustainable development, and has important application in the chemical industry. Much research is currently being devoted to the conversion of lignin into high value-added aromatic products and fuels, including Hydrodeoxygenation (HDO), esterification, catalytic cracking, and the like. Most of these conversion processes need to be carried out under catalytic conditions. Therefore, the preparation and selection of a suitable catalyst is a key factor in the lignin degradation process.

Lignin is one of the most structurally complex of woody biomass and its high oxygen content limits its widespread use. Anisole has the most typical C-O bond structure and benzene ring structure in lignin, so that in our research, a small molecular model compound, namely anisole, is used for testing the hydrodeoxygenation capacity of the catalyst, and a basis is provided for catalytic conversion and utilization of lignin.

In the past exploration, catalysts commonly used in the hydrodeoxygenation reaction of lignin are noble metal catalysts, metal borides, sulfides, carbides, and phosphides. The transition metal sulfide catalyst is a low-cost catalyst and has good hydrodeoxygenation capacity, and is widely applied to petroleum refining. Among transition metal sulfide catalysts, molybdenum-based catalysts have been most studied. Particularly, when the catalyst is supplemented with promoters such as Ni, Co and the like, the catalyst shows stronger hydrodeoxygenation capacity. Many researchers also improve the catalytic performance of the catalyst by changing the morphology and changing the carrier. The catalysts with different shapes have different specific surface areas and active site numbers, different carriers have different acid-base properties and different interactions between the catalysts and the carriers, and different changes of the catalysts have different influences on the distribution and selectivity of products.

However, sulfide catalysts also have certain problems in the reaction. Firstly, the yield of the phenolic high value-added chemicals is low after the reaction is finished, and the loss of sulfur in the catalyst can cause the activity of the catalyst to be reduced. Therefore, in the research of sulfide catalysts, how to improve the yield of target products and control the loss of sulfur in the reaction to prolong the service life of the catalysts becomes a key problem of breakthrough needed by the research.

Disclosure of Invention

In order to solve the problems in the prior art, explore a molybdenum disulfide catalyst with a novel structure and a novel morphology, further improve the utilization rate of biomass energy and improve the yield of phenolic chemicals, the invention provides a molybdenum disulfide-niobic acid catalyst and a method thereof in the application of preparing the phenolic chemicals through catalytic conversion of lignin.

In order to achieve the purpose, the invention adopts the technical scheme that: the invention relates to a molybdenum disulfide-niobic acid catalyst, and a preparation method of the catalyst, which comprises the following steps:

1) weighing tin niobate, adding the tin niobate into a polytetrafluoroethylene lining, adding ammonium molybdate and thiourea, adding a hydrochloric acid solution to adjust the pH value to 0.7-1.0, and putting the mixture into a kettle for reaction to obtain a black precipitate;

2) carrying out suction filtration and washing on the black precipitate obtained after the reaction in the step 1), placing the black precipitate in a vacuum drying oven, and drying to obtain MoS₂-H₄Nb₂O₇A catalyst.

The hydrothermal reaction temperature in the step 1) is 100-;

the mass ratio of the metal salt to the tin niobate in the step 1) is 5: 1-20: 1, and the mass ratio of the thiourea to the metal salt is 0.4: 1-2: 1; adding 0.1-0.2 mol/L hydrochloric acid solution, wherein the ratio of the volume of the hydrochloric acid to the addition amount of the tin niobate is 50-300 mL/g

The temperature of the drying in the step 2) is 60-120 ℃, and the time is 6-12 h.

An application of a molybdenum disulfide-niobic acid catalyst in anisole hydrodeoxygenation specifically comprises the following steps:

1) weighing a catalyst, adding the catalyst into an intermittent high-pressure reaction kettle, adding an anisole solution, and filling the reaction kettle;

2) the reaction is carried out under the conditions that the initial pressure of hydrogen is 1-6MPa, the reaction temperature is 150-.

In the step 1), the reaction internal standard substance in the anisole solution is n-dodecane, and the solvent used in the anisole solution is one of methylcyclohexane, n-hexane, decalin, methanol and ethanol, or the mixture of the above solvents in any proportion;

the mass ratio of the anisole to the catalyst in the step 1) is 1:1-10: 1; the concentration range of the anisole solution is 0.05-0.15mol/L

The invention has the following remarkable advantages:

1. the reaction solvent is a common organic solvent, is pollution-free and environment-friendly, and does not use any acid or alkaline substances in the reaction process, so that the problem of environmental pollution in the process is avoided.

2. The conversion rate of the lignin monomer anisole is high, phenols in the product are main products, the catalyst has strong selectivity for the reaction, and the main products are chemicals with high added values and are widely applied in industry, so the catalyst has good industrial application prospect.

3. When the application is carried out under the test conditions of 270 ℃, 3MPa and 4 hours, the yield of the phenol can still be kept at 90 percent, and compared with the application of a common molybdenum disulfide catalyst in the anisole hydrodeoxygenation reaction, the yield of the phenol is improved by more than 20 percent.

Drawings

FIG. 1 is a graph showing the results of various examples of the present invention.

Detailed Description

In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.