CN113754514A - Method for preparing pentanol from 2-methylfuran at room temperature by adopting supported catalyst - Google Patents

Method for preparing pentanol from 2-methylfuran at room temperature by adopting supported catalyst Download PDF

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CN113754514A
CN113754514A CN202111048619.6A CN202111048619A CN113754514A CN 113754514 A CN113754514 A CN 113754514A CN 202111048619 A CN202111048619 A CN 202111048619A CN 113754514 A CN113754514 A CN 113754514A
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王川
吴敏
张斌
汪婷
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Nanjing Tech University
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Abstract

The invention provides a method for preparing pentanol from 2-methylfuran at room temperature by adopting a supported platinum-based catalyst. The influence of various catalyst supports, active metals, metal loadings and reaction conditions (solvents, time, pressure, etc.) was examined. The acid treatment time of the 5 wt% Pt/MWNT catalyst on the MWNT was found to be 4 hours at 1MPa H2Excellent activity and selectivity at ultralow temperature of 25 ℃ under pressure, 100% conversion of 2-MF and 53% yield of Pentanols (POLs). The invention provides a brand new route for synthesizing the amyl alcohol, and compared with the traditional synthesis process route, the process route has the advantages of simple preparation process, milder reaction condition, greatly reduced energy consumption and environmental friendliness. The Pt/MWNT catalyst of the invention has good reusability, which shows thatIts potential for industrial applications.

Description

Method for preparing pentanol from 2-methylfuran at room temperature by adopting supported catalyst
Technical Field
The invention belongs to the field of biomass energy catalysis, and relates to a method for preparing pentanol by selectively cracking C-O with 2-methylfuran at room temperature by using a supported catalyst.
Background
Lignocellulosic biomass, as the largest renewable carbon resource, has attracted considerable interest in the efficient conversion of lignocellulosic biomass into chemical products with high added values, which can alleviate the severe dependence on fossil resources and the associated environmental impact. In particular, much work has been devoted to upgrading lignocellulose derived furan derivatives, such as 2-methylfuran (2-MF), to fuels and valuable chemicals.
Pentanols (POLs) have been widely used as fuel additives, food additives and organic solvents due to their unique properties of relatively low viscosity and high volatility. Traditionally, pentanol is prepared by bio-enzymatic fermentation, however, the enzymes are very demanding on the environment and are prone to inactivation. In addition, the separation of pentanol from petroleum is very difficult and expensive due to the complicated process flow and separation steps. This reduces the economic advantage of the process. To solve these problems, the chemical process for the preparation of linear alcohols by catalytic ring opening of furan compounds has become an effective alternative. Noble metal catalysts such as ruthenium, palladium, platinum and the like and non-noble metal catalysts have the activity of catalyzing open loop of furan compounds to produce pentanol. For example, Pd-Fe/Al2O3The alloy was converted to 2-MF at 200 ℃ and the yield of pentanol in the tubular flow reactor was 39% (Appl Catal A Gen.2017; 543(6): 133.). Kang et Al (ChemCatchem.2017; 9(2):282.) observed Pt/Al prepared by atomic layer deposition method2O3The catalyst, with a Pt loading of 0.47%, provided a pentanol yield of approximately 25% at 180 ℃. Pentanol is obtained from 2-THMF on Rh-ReOx/C catalyst in yields of only 12% (J Am Chem Soc.2011; 133(32):12675.) even under optimized reaction conditions. Zhang et al (Chemussem.2018; 11(4):726.) reported 2-methyltetrahydrofuran in Pd/C and Sc (OTf)3High yield of 1-pentanol (81%) obtained by a two-step process on a co-catalytic system. However, at 150 ℃ a high H is applied2Pressure (3MPa) to activate 2-THMF. Non-noble metals such as Cu/Cr/Ni/Zn/Fe were developed to catalyze the gas phase ring opening of 2-MF, which provides 25% pentanol yield at 200 deg.C, but due to the conversion of pentanol to ketonization at higher temperaturesThe instability of the compound decreased to 10% at 250 ℃ (Appl Catal A Gen.2014; 475(1): 379.). Recently, Seemala et Al (React Chem Eng.2019; 2(4):261.) used a Co-Cu/Al 2O3 catalyst for furfural ring opening at 240 ℃ and 4.5MPa H2The desired 2-pentanol yield of 71% is obtained. Despite many advances, these processes are still subject to high temperatures and high hydrogen pressures.
In view of the problems existing at present, the development of a method for converting furan derivatives into pentanol under mild conditions has important research value and application potential.
Disclosure of Invention
In order to solve the technical problem, the invention provides a method for preparing amyl alcohol by ring opening of 2-MF at room temperature by adopting a supported catalyst. To achieve the following objects:
(1) reducing the reaction temperature and pressure;
(2) the yield of the amyl alcohol is improved;
(3) the catalyst has high activity and long service life, can be continuously applied and reduces the production cost;
a process for the preparation of pentanol from 2-methylfuran using a supported catalyst at room temperature, we studied systematically H at room temperature and mildness22-MF selective C-O cracking to pentanol over a range of Pt-based catalysts under pressure. First, various carriers (MgO, Al)2O3、SiO2MWNT) and noble metals (Pd, Ru, Pt, Rh) found the highest pentanol yield for the Pt/MWNT catalyst, while the main product of Pt on other supports was 2-THMF. The optimized Pt/MWNT catalyst is intensively researched. The influence of different MWNT acid treatment times and Pt loading on the 2-MF hydrogenolysis reaction was examined. The results show that the acid treatment time of the optimized 5 wt% Pt/MWNT on the MWNT is 4 hours, and 100% conversion rate and 53% yield can be realized at the ultra-low temperature of 25 ℃. In addition, the influence of reaction conditions such as reaction solvent, time and pressure on the selective hydroconversion of 2-MF on Pt/MWNT was also investigated.
In order to solve the technical problem of the invention, the technical scheme is as follows: adding 2-methylfuran and isopropanol serving as solvents and 5 wt% of Pt/MWNT catalyst into a reaction kettle, and packaging and sealing; replacing with 1-2MPa hydrogen for multiple times, charging 1MPa hydrogen into the kettle, reacting at 25 deg.C for 3h, cooling, relieving pressure, opening the kettle, and filtering; the preparation method of the 5 wt% Pt/MWNT catalyst comprises the steps of adding concentrated nitric acid into each gram of carbon nano tube according to the proportion of adding 100ml of nitric acid, installing a round-bottom flask into an oil bath pan, stirring, condensing and refluxing for 4 hours, quickly adding deionized water to cool and dilute the acid concentration after purification is finished, repeatedly washing and filtering the carbon nano tube until the final filtrate is neutral, and drying at 70-90 ℃ for 8-12 hours; taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, sieving to prepare a carbon nano tube carrier, and synthesizing the platinum-based catalyst by adopting an incipient wetness impregnation method by taking tetramine platinum (II) nitrate as a precursor solution.
Preferably, the method comprises the following steps:
(1) adding multi-walled carbon nanotubes and concentrated nitric acid into a round-bottom flask, adding the concentrated nitric acid according to the proportion that 100ml of nitric acid is added into each gram of carbon nanotubes, arranging the round-bottom flask in an oil bath, stirring, and carrying out condensation reflux for 4 hours; after the purification is finished, rapidly adding deionized water for cooling and diluting the acid concentration, repeatedly cleaning and filtering the carbon nano tubes until the final filtrate is neutral, and drying for 8-12 hours at 70-90 ℃; taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and sieving to prepare a carbon nano tube carrier;
(2) then, taking tetramine platinum (II) nitrate as a precursor solution, and synthesizing a platinum-based catalyst by adopting an incipient wetness impregnation method; introducing nitrogen into a tubular furnace, and calcining at the temperature of 350 ℃ and 450 ℃ for 3-5 h; then introducing hydrogen to reduce at 250 ℃; after cooling to room temperature, the 5% wt Pt/MWNT catalyst was collected in a dry box.
(3) The liquid phase ring opening of the 2-methylfuran is carried out in a reaction kettle provided with a heat conduction detector; typically, 0.25 mol% of a 5% wt Pt/MWNT metal catalyst, 2-methylfuran and the solvent isopropanol are added to the reaction kettle; purging the reactor with hydrogen several times to remove air from the reactor prior to the reaction; in the reaction process, the hydrogen pressure is 1MPa, the temperature is kept at 25 ℃, and the reaction time is 3 h.
(4) After the reaction, the catalyst and the reaction solution were separated by centrifugation.
Preferably, the method comprises the following steps:
(1) adding 2g of multi-walled carbon nanotube and 200mL of nitric acid into a round-bottom flask, arranging the round-bottom flask in an oil bath, stirring at 120 ℃, and carrying out condensation reflux for 4 hours; after the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g of the platinum precursor solution is dissolved in 100mL of deionized water to prepare a platinum precursor solution Pt: 25.19mg/mL for use;
(3) weighing 950mg of multi-walled carbon nanotube carrier, uniformly spreading the carrier on a mortar, taking 2mL of platinum precursor solution, performing ultrasonic oscillation before taking, adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the solution, uniformly dropwise adding the platinum solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(5) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on a catalyst bed layer, introducing nitrogen at a flow rate of 60mL/min, heating at a temperature rise rate of 5 ℃/min, raising the temperature from room temperature to 400 ℃, calcining at 400 ℃ in a nitrogen atmosphere of 60mL/min for 5h, cooling to 250 ℃, reducing with hydrogen at a rate of 40mL/min for 1h, cooling to room temperature, and taking out to obtain a 5 wt% Pt/MWNT catalyst;
(6) the liquid phase ring opening of the 2-MF is carried out in a reaction kettle provided with a heat conduction detector; adding 50mg of 5% wt Pt/MWNT catalyst, 4mmol of 2-methylfuran and 8mL of isopropanol into a reaction kettle, purging the reactor for 3 times by using hydrogen to remove air in the reactor before reaction, and then filling 1MP of hydrogen pressure, keeping the temperature at 25 ℃ and reacting for 3 hours;
(7) after the reaction, the catalyst and the reaction solution were separated by centrifugation.
Preferably, the liquid phase ring opening of 2-MF in step (6) is carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5 wt% Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard.
Preferably, after the reaction of step (7), the catalyst and the reaction solution are separated by centrifugation; the catalyst powder was filtered off and the reaction results were analyzed by gas chromatography, GC; the recovered catalyst filtrate was continuously washed with isopropanol and then dried overnight in a vacuum oven at 60 ℃.
Has the advantages that:
(1) the invention provides a brand new route for synthesizing the amyl alcohol, and compared with the traditional synthesis process route, the process route has the advantages of simple preparation process, milder reaction condition, greatly reduced energy consumption and environmental friendliness. The general reaction formula of the invention is as follows:
Figure BDA0003251881170000051
(2) the invention can realize 100 percent of 2-MF conversion rate and 53 percent of amyl alcohol yield at 5wt percent of optimized Pt/MWNT and ultralow temperature of 25 ℃. A highly efficient catalyst capable of effectively cleaving C-O bonds under mild conditions was developed.
(3) The Pt/MWNT catalyst has good reusability, can be widely subjected to ring opening in different furan derivatives (furan, 2, 5-dimethylfuran, furfural, 2-ethylfuran and the like) at room temperature, and shows wide potential in industrial application. This work also provided the idea of designing efficient catalysts for room temperature biofuel production.
(4) The effect of solvents on 2-MF hydrogenolysis on Pt/MWNT catalysts was investigated using five typical solvents, including aprotic solvents: p-xylene, acetonitrile and protic solvents: isopropanol, ethanol and water. The results indicate that isopropanol is the most effective reaction medium on Pt/MWNT catalysts.
(5) It can be seen from figure 5 that as the platinum loading increased from 1 wt% to 5 wt%, the 2-MF conversion increased from 30% to 100%, and the pentanol yield increased from 11% to 53%. However, as the Pt loading increased to 10%, the 2-MF conversion and pentanol yield decreased slightly. This is due to the partial agglomeration of platinum nanoparticles at higher metal loadings (Pt 10 wt%) resulting in an increase in metal particle size. Therefore, 5% Pt/MWNT with the appropriate Pt dispersion state and metal particle size facilitates the conversion and selective C-O bond hydrogenolysis process.
(6) As the acid treatment time was increased from 2h (Pt/MWNT-2) to 4h (Pt/MWNT-4), the 2-MF conversion gradually increased from 91% to 100%, and the POLs yield gradually increased from 42% to 53%. However, as the acid treatment time was further increased to 6h (Pt/MWNT-6), both the 2-MF conversion and the POL yield slightly decreased. Too much acid treatment time resulting in too strong hydrophilicity of the catalyst may result in reactants and H2Competitive adsorption of O molecules. In addition, over-treatment may also disrupt the porous structure of the MWNT support, thereby altering the Pt-MWNT interaction, e.g., altering the platinum particle size held on the MWNT. The above results show that the optimized catalyst 5 wt% Pt/MWNT-4 has proper metal particle size and hydrophilicity and finely dispersed metal positions, can promote 2-MF conversion and increase pentanol yield.
(7) Fig. 7 and 8 show the curves of conversion and selectivity as a function of reaction time and reaction pressure. The 2-MF conversion increased with longer reaction times. Only 16% conversion was achieved in the first 0.25 hours, and finally near 100% at the end of the third hour. At a low pressure of 0.1MPa, the conversion of 2-MF was 16% and the yield of POLs was 8%. When the pressure was increased to 1.0MPa, the conversion increased significantly to 100% and the yield of the POLs increased to 53%. Therefore, the optimum reaction time was 3 hours, and the optimum reaction hydrogen pressure was 1 MPa.
(8) The liquid phase ring opening of the 2-MF is carried out in a reaction kettle provided with a heat conduction detector, the reaction temperature and the reaction time can be accurately controlled, reactants in the reactor are continuously subjected to multi-step reaction, the tedious separation process and the purification process of intermediate compounds in the post-treatment process can be avoided, the time and the resources are saved, and the yield is improved. The present invention is a chemical reaction strategy for continuously carrying out multi-step reactions of reactants in a reactor to improve reaction efficiency.
Drawings
FIG. 1 is a schematic view of a supported catalyst preparation apparatus
FIG. 2 shows the evaluation of catalytic performance of platinum-based catalysts with different carriers in the preparation of pentanol by 2-MF selective ring opening
FIG. 3 shows NH of platinum-based catalysts with different supports3TPD diagram
FIG. 4 is a Transmission Electron Microscopy (TEM) image of a platinum-based catalyst on different supports
FIG. 5 is a graph of the effect of platinum loading on conversion and selectivity
FIG. 6 is a graph of the effect of acid treatment time on conversion and selectivity for multiwall carbon nanotubes (MWNT)
FIG. 7 is a graph showing the effect of reaction time on catalytic activity
FIG. 8 is a graph showing the effect of reaction pressure on catalytic activity
FIG. 9 is a graph showing the effect of reaction solvent on catalytic activity
FIG. 10 shows the results of the catalyst stability test
FIG. 11 is a diagram of a possible reaction pathway for 2-MF ring opening on Pt/MWNT catalysts
Detailed Description
The present invention will be described in further detail with reference to specific examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present invention.
Example 1
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 4 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 950mg of multi-walled carbon nanotube carrier, uniformly spreading the carrier on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution, uniformly dropwise adding the platinum precursor solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 h;
(5) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 5 wt% Pt/MWNT catalyst.
(6) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5% wt Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(7) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Example 2: the present embodiment differs from embodiment 1 in that: the reaction time was 15min, and the rest was the same as in example 1.
Example 3: the present embodiment differs from embodiment 1 in that: the reaction time was 30min, and the rest was the same as in example 1.
Example 4: the present embodiment differs from embodiment 1 in that: the reaction time was 1 hour, and the rest was the same as in example 1.
Example 5: the present embodiment differs from embodiment 1 in that: the reaction time was 2 hours, and the rest was the same as in example 1.
Example 6: the present embodiment differs from embodiment 1 in that: the reaction pressure was 0.1MPa, and the rest was the same as in example 1.
Example 7: the present embodiment differs from embodiment 1 in that: the reaction pressure was 0.25MPa, and the rest was the same as in example 1.
Example 8: the present embodiment differs from embodiment 1 in that: the reaction pressure was 0.5MPa, and the rest was the same as in example 1.
Example 9: the present embodiment differs from embodiment 1 in that: the reaction pressure was 2MPa, and the rest was the same as in example 1.
Example 10: the present embodiment differs from embodiment 1 in that: the reaction pressure was 3MPa, and the rest was the same as in example 1.
Example 11: the present embodiment differs from embodiment 1 in that: the solvent was p-xylene (PX), the rest being the same as in example 1.
Example 12: the present embodiment differs from embodiment 1 in that: the solvent was Acetonitrile (ATL), the other was the same as in example 1.
Example 13: the present embodiment differs from embodiment 1 in that: the solvent was ethanol, and the rest was the same as in example 1.
Example 14: the present embodiment differs from embodiment 1 in that: the solvent was water, and the rest was the same as in example 1.
Example 15: the present embodiment differs from embodiment 1 in that: the reactant was furan, otherwise the same as in example 1.
Example 16: the present embodiment differs from embodiment 1 in that: the reactant was 2, 5-dimethylfuran, the rest being the same as in example 1.
Example 17: the present embodiment differs from embodiment 1 in that: the reactant was 2-ethylfuran, the rest being the same as in example 1.
Example 18: the present embodiment differs from embodiment 1 in that: the reactant was furfural, the other was the same as in example 1.
Examples 15-18 results of various substrate hydrocracking reactions:
Figure BDA0003251881170000101
example 19
The procedure is as in example 1, the recovered catalyst is continuously rinsed with isopropanol and then dried in a vacuum oven at 60 ℃ for 12 hours. Cycling experiments were performed under the same conditions. But the catalyst is recycled for the 2 nd time, and the yield of the amyl alcohol product is 52 percent.
EXAMPLE 20 the procedure of example 11 was followed, but the catalyst was recovered for the 3 rd cycle, resulting in a pentanol product yield of 49%.
EXAMPLE 21 the procedure of example 11 was followed except that the catalyst was recovered for the 4 th cycle, resulting in a pentanol product yield of 48%.
EXAMPLE 22 the procedure of example 11 was followed, but the catalyst was recovered for the 5 th cycle, giving a yield of pentanol product of 47%.
Comparative example 1
(1) Taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(2) weighing Al2O3Uniformly spreading a carrier of 950mg on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution and the deionized water, uniformly dropwise adding the platinum solution onto the carrier, grinding until the catalyst is fully impregnated, and drying in a drying oven at 70 ℃ for 12 h;
(3) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, filling quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, cooling the catalyst bed layer to the room temperature, taking out the catalyst bed layer to obtain the 5 wt% Pt/Al2O3A catalyst.
(4) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. 50mg of 5% wt Pt/Al are added to the reactor2O3Catalyst, 4mmol 2-MF and 8mL isopropanol, and a certain amount of dodecane was added as an internal standard. Before the reaction, usePurging the reactor with hydrogen for 3 times to remove air in the reactor, and charging hydrogen at 1MPa for 3h at 25 deg.C.
(5) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 2
(1) Taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(2) weighing SiO2Uniformly spreading a carrier of 950mg on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution and the deionized water, uniformly dropwise adding the platinum solution onto the carrier, grinding until the catalyst is fully impregnated, and drying in a drying oven at 70 ℃ for 12 h;
(3) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, filling quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, cooling the catalyst bed layer to the room temperature, taking out the catalyst bed layer to obtain the 5 wt% Pt/SiO22A catalyst.
(4) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. 50mg of 5% wt Pt/SiO in the reactor2Catalyst, 4mmol 2-MF and 8mL isopropanol, and a certain amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(5) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 3
(1) Taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(2) weighing 950mg of MgO carrier, uniformly spreading the MgO carrier on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution, uniformly dropwise adding the platinum solution on the carrier, grinding the platinum precursor solution until the catalyst is fully impregnated, and drying the platinum precursor solution in a drying oven at 70 ℃ for 12 h;
(3) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, filling quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of 400 ℃ nitrogen (60mL/min), then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at the rate of 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 5 wt% Pt/MgO catalyst.
(4) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5% wt Pt/MgO catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(5) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 4
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 4 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 990mg of MWNT carrier, uniformly spreading the MWNT carrier on a mortar, taking 0.397mL of platinum precursor solution (oscillating and ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic for 5min to uniformly mix the platinum precursor solution and the deionized water, uniformly dropwise adding the platinum precursor solution on the carrier, grinding until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(4) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 1 wt% Pt/MWNT catalyst.
(5) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 1% wt Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(5) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 5
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 4 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 970mg of MWNT carrier, uniformly spreading the MWNT carrier on a mortar, taking 1.19mL of platinum precursor solution (oscillation and ultrasonic treatment before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution and the deionized water, uniformly dropwise adding the platinum precursor solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(4) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 3 wt% Pt/MWNT catalyst.
(5) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 3% wt Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(6) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 7
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 4 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 900mg of MWNT carrier, uniformly spreading the MWNT carrier on a mortar, taking 3.97mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution and the deionized water, uniformly dropwise adding the platinum precursor solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(4) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 10 wt% Pt/MWNT catalyst.
(5) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 10% wt Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(6) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 8
(1) Taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 950mg of original multi-walled carbon nanotubes, uniformly spreading the original multi-walled carbon nanotubes on a mortar, taking 2mL of platinum precursor solution (obtained by oscillating ultrasonic before), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the solution, uniformly dropwise adding the platinum solution on a carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(5) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 5 wt% Pt/MWNT-0 catalyst.
(6) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5% wt Pt/MWNT-0 catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(7) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 9
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 2 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 950mg of multi-walled carbon nanotube carrier, uniformly spreading the carrier on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution, uniformly dropwise adding the platinum precursor solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 h;
(4) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 5 wt% Pt/MWNT-2 catalyst.
(5) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5% wt Pt/MWNT-2 catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(6) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
Comparative example 10
(1) 2g of multi-walled carbon nanotubes and 200mL of nitric acid were added to a round-bottom flask, the flask was placed in an oil bath, stirred at 120 ℃ and refluxed by condensation for 6 hours. After the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g was dissolved in 100mL of deionized water, and prepared as a platinum precursor solution (Pt: 25.19mg/mL) for use;
(3) weighing 950mg of multi-walled carbon nanotube carrier, uniformly spreading the carrier on a mortar, taking 2mL of platinum precursor solution (oscillating ultrasonic before taking), adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the platinum precursor solution, uniformly dropwise adding the platinum precursor solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 h;
(5) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on the upper part and the lower part of a catalyst bed layer, introducing nitrogen (the flow rate is 60mL/min, the heating rate is 5 ℃/min), heating the catalyst bed layer to 400 ℃ from room temperature, calcining the catalyst bed layer for 5 hours in the atmosphere of nitrogen (60mL/min) at 400 ℃, then cooling the catalyst bed layer to 250 ℃, reducing the catalyst bed layer for 1 hour by using hydrogen at 40mL/min, and taking out the catalyst bed layer after cooling to room temperature to obtain the 5 wt% Pt/MWNT-6 catalyst.
(6) The liquid phase ring opening of 2-MF was carried out in a reaction vessel equipped with a thermal conductivity detector. To the reaction kettle was added 50mg of 5% wt Pt/MWNT-6 catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard. Before the reaction, the reactor was purged with hydrogen 3 times to remove air in the reactor, and then charged with 1MPa of hydrogen pressure, the temperature was maintained at 25 ℃ and the reaction time was 3 hours.
(7) After the reaction, the catalyst and the reaction solution were separated by centrifugation. The catalyst powder was filtered off and the filtrate was analyzed using a Flame Ionization Detector (FID) equipped with a Gas Chromatograph (GC) of HP-5 capillary column. The by-products were analyzed by GC-MS (Agilent, 6890N 5973).
According to the experimental results of FIG. 2, 2-MF was completely converted at room temperature on Pt/MWNT catalyst, and the yield of POLs was 53%. While the conversion of the other three platinum oxide supported catalysts varied from 11% to 90%, and the yield of the POLs varied from 7% to 28%. These oxide supports favor the hydrogenation of the furan ring to 2-THMF rather than the selective hydrogenolysis of the C-O bond. In particular toFor example, both the 2-MF conversion and the selectivity to POLs decrease in the following order: Pt/MWNT>Pt/SiO2>Pt/Al2O3>Pt/MgO
According to FIG. 3, to explore the intrinsic effect of the vector, NH was used3TPD measures the acidity of Pt supported catalysts and is generally considered to have three peak regions, namely, peak regions belonging to a weak acid site (40-200 ℃), a medium acid site (200-400 ℃) and a strong acid site (400-800 ℃). The acidity summarized in Table 1 indicates Pt/Al2O3The acidity of (2) was highest at 4.65mmol/g, while Pt/MgO showed the lowest acidity of 0.39 mmol/g. The total acidity of Pt/MWNT is 0.97 mmol/g. Different acidity affects the adsorption and activation of reactants on the catalyst surface, resulting in a change in selectivity. Pt/Al2O3Too many acid sites on the surface may result in different competing adsorption patterns of 2-MF on the surface, thereby adversely affecting the selectivity of the POLs. Meanwhile, too few acid sites on Pt/MgO and Pt/SiO2 may hinder the adsorption of 2-MF, resulting in low conversion and selectivity. In addition, a suitable number of acidic sites on the surface of MWNTs can accommodate Pt anchoring, thereby facilitating subsequent C — O bond activation. Thus, Pt/MWNT containing appropriate amounts of acid centers favor the conversion of 2-MF and the selective hydrogenolysis reaction to pentanol.
TABLE 1
Figure BDA0003251881170000201
According to a Transmission Electron Microscope (TEM) image of FIG. 4, the average Pt particle size is Pt/MWNT<Pt/Al2O3<Pt/SiO2<Pt/MgO. The Pt particles on Pt/MWNTs were the smallest, less than 3nm (2.2nm), while the Pt particles on the other three catalysts were larger in size (3 nm). It can be concluded from this that smaller Pt nanoparticles favor the selective cleavage of C — O into POLs, while larger Pt nanoparticles: (>3nm) favours ring hydrogenation to 2-THMF.
It can be seen from figure 5 that as the platinum loading increased from 1 wt% to 5 wt%, the 2-MF conversion increased from 30% to 100%, and the pentanol yield increased from 11% to 53%. The low conversion and low POLs formation of 1 wt% Pt/MWNT and 3 wt% Pt/MWNT are due to their insufficient active sites. However, as the Pt loading increased to 10%, the 2-MF conversion and pentanol yield decreased slightly. This is due to the partial agglomeration of platinum nanoparticles at higher metal loadings (Pt 10 wt%) resulting in an increase in metal particle size. Therefore, 5% Pt/MWNT with the appropriate Pt dispersion state and metal particle size facilitates the conversion and selective C-O bond hydrogenolysis process.
According to the results of FIG. 6, no 2-MF conversion was observed for the untreated Pt/MWNT-0 catalyst due to the hydrophobicity of its original MWNT support, which inhibited Pt adsorption on the surface. As the acid treatment time was increased from 2h (Pt/MWNT-2) to 4h (Pt/MWNT-4), the 2-MF conversion gradually increased from 91% to 100%, and the POLs yield gradually increased from 42% to 53%. However, as the acid treatment time was further increased to 6h (Pt/MWNT-6), both the 2-MF conversion and the POL yield slightly decreased. Too much acid treatment time resulting in too strong hydrophilicity of the catalyst may result in reactants and H2Competitive adsorption of O molecules. In addition, over-treatment may also disrupt the porous structure of the MWNT support, thereby altering the Pt-MWNT interaction, e.g., altering the platinum particle size held on the MWNT. The above results show that the optimized catalyst 5 wt% Pt/MWNT-4 has proper metal particle size and hydrophilicity and finely dispersed metal positions, can promote 2-MF conversion and increase pentanol yield.
Fig. 7 and 8 show the curves of conversion and selectivity as a function of reaction time and reaction pressure. The 2-MF conversion increased with longer reaction times. Only 16% conversion was achieved in the first 0.25 hours, and finally near 100% at the end of the third hour. At a low pressure of 0.1MPa, the conversion of 2-MF was 16% and the yield of POL was 8%. When the pressure was increased to 1.0MPa, the conversion increased significantly to 100% while the yield of the POLs increased slightly to 53%. Therefore, the optimum reaction time was 3 hours, and the optimum reaction hydrogen pressure was 1 MPa.
According to the results of fig. 9, the effect of solvents on 2-MF hydrogenolysis on Pt/MWNT catalysts was investigated using five typical solvents, including aprotic solvents: p-xylene, acetonitrile and protic solvents: isopropanol, ethanol and water. The lowest 2-MF conversion (5%) and pentanol yield (0%) were obtained in p-xylene solvent. A low conversion of 54% and a yield of pentanol of only 13% was also observed in other aprotic acetonitrile solvents. In contrast, protic solvents provided complete 2-MF conversion and higher pentanol yields varied from 43% to 53%. Of the three protic solvents, the highest pentanol yield (53%) was detected in isopropanol medium. The water, although most polar, gave slightly lower pentanol yields. The difference in selectivity is probably due to the higher hydrogen solubility of isopropanol (4.61) than ethanol (2.06) and water (0.14). In addition, the relatively high water density may create additional diffusion limitations on the reaction, thereby hindering 2-MF hydrogenolysis. In our example, we found that protons in the solvent and their hydrogen solubility have a considerable influence on the activity and selectivity, whereas isopropanol is the best reaction solvent on Pt/MWNT catalysts.
According to the results of the cyclic catalyst recycle reaction of FIG. 10, the 2-MF conversion rate was slightly reduced after 5 continuous runs, from 100% to 96%, while the pentanol yield was still 47%. Indicating that the Pt/MWNT catalyst has good reusability.
According to the reaction result and relevant characteristics, a series of supported platinum-based catalysts are prepared by an incipient wetness impregnation method, the supported platinum-based catalysts are applied to a 2-methylfuran ring-opening hydrogenation model reaction, through optimization of reaction conditions, ring opening of 2-MF can be realized at room temperature, and the optimized 5 wt% Pt/MWNT-4 can realize 100% conversion rate and 53% yield at ultralow temperature of 25 ℃ under hydrogen pressure of 1MPa by taking isopropanol as a solvent. Compared with previous researches, the ring-opening reaction usually requires conditions such as high temperature and high pressure. But the preparation process of the process route is simple, the reaction condition is milder, the energy consumption is greatly reduced, and the method is more environment-friendly. In addition, the Pt/MWNT catalyst has good reusability, can be widely subjected to ring opening in different furan derivatives (furan, 2, 5-dimethylfuran, furfural, 2-ethylfuran and the like) at room temperature, and shows wide potential in industrial application. A promising catalyst is shown for room temperature biofuel production.

Claims (5)

1. A process for preparing pentanol from 2-methylfuran using a supported catalyst at room temperature, characterized by: adding 2-methylfuran and isopropanol serving as solvents and 5 wt% of Pt/MWNT catalyst into a reaction kettle, and packaging and sealing; replacing with 1-2MPa hydrogen for multiple times, charging 1MPa hydrogen into the reaction kettle, reacting at 25 deg.C for 3h, cooling, relieving pressure, opening the kettle, and filtering; the preparation method of the 5 wt% Pt/MWNT catalyst comprises the steps of adding concentrated nitric acid in a proportion that 100mL nitric acid is added into each gram of carbon nano tube, installing a round-bottom flask in an oil bath pan, stirring, condensing and refluxing for 4 hours, quickly adding deionized water to cool and dilute the acid concentration after purification is finished, repeatedly washing and filtering the carbon nano tube until the final filtrate is neutral, and drying at 70-90 ℃ for 8-12 hours; taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, sieving to prepare a carbon nano tube carrier, and synthesizing the multi-wall carbon nano tube supported platinum-based catalyst by adopting an incipient wetness impregnation method by taking tetramine platinum (II) nitrate as a precursor solution.
2. The process for the preparation of pentanol from 2-methylfuran at room temperature using a supported catalyst according to claim 1, wherein: the method comprises the following steps:
(1) adding multi-walled carbon nanotubes and concentrated nitric acid into a round-bottom flask, adding the concentrated nitric acid according to the proportion that 100ml of nitric acid is added into each gram of carbon nanotubes, arranging the round-bottom flask in an oil bath, stirring, and carrying out condensation reflux for 4 hours; after the purification is finished, rapidly adding deionized water for cooling and diluting the acid concentration, repeatedly cleaning and filtering the carbon nano tubes until the final filtrate is neutral, and drying for 8-12 hours at 70-90 ℃; taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and sieving to prepare a carbon nano tube carrier;
(2) then, taking tetramine platinum (II) nitrate as a precursor solution, and synthesizing a platinum-based catalyst by adopting an incipient wetness impregnation method; introducing nitrogen into a tubular furnace, and calcining at the temperature of 350 ℃ and 450 ℃ for 3-5 h; then introducing hydrogen to reduce at 250 ℃; after cooling to room temperature, the 5% wt Pt/MWNT catalyst was collected in a drying oven;
(3) the liquid phase ring opening of the 2-methylfuran is carried out in a reaction kettle provided with a heat conduction detector; typically, 0.25 mol% of a 5% wt Pt/MWNT metal catalyst, 2-methylfuran and the solvent isopropanol are added to the reactor; purging the reactor with hydrogen several times to remove air from the reactor prior to the reaction; in the reaction process, the hydrogen pressure is 1MPa, the temperature is kept at 25 ℃, and the reaction time is 3 h;
(4) after the reaction, the catalyst and the reaction solution were separated by centrifugation.
3. The process for the preparation of pentanol from 2-methylfuran at room temperature using a supported catalyst according to claim 1, wherein: the method comprises the following steps:
(1) adding 2g of multi-walled carbon nanotube and 200mL of nitric acid into a round-bottom flask, arranging the round-bottom flask in an oil bath, stirring at 120 ℃, and carrying out condensation reflux for 4 hours; after the purification is finished, deionized water is quickly added for cooling and diluting the acid concentration, the carbon nano tubes are repeatedly washed and filtered until the final filtrate is neutral, and the carbon nano tubes are dried in an oven at the temperature of 70 ℃ for 12 hours. Taking out the dried carbon nano tube, putting the carbon nano tube into a mortar for grinding, and preparing a carbon nano tube carrier after sieving the carbon nano tube by a standard sieve with 100 meshes;
(2) taking tetramine platinum nitrate (Pt (NH)4)4(NO3)2)5g of the platinum precursor solution is dissolved in 100mL of deionized water to prepare a platinum precursor solution Pt: 25.19mg/mL for use;
(3) weighing 950mg of multi-walled carbon nanotube carrier, uniformly spreading the carrier on a mortar, taking 2mL of platinum precursor solution, performing ultrasonic oscillation before taking, adding 5mL of deionized water for dilution, performing ultrasonic treatment for 5min to uniformly mix the solution, uniformly dropwise adding the platinum solution on the carrier, grinding the carrier until the catalyst is fully impregnated, and drying the carrier in a drying oven at 70 ℃ for 12 hours;
(5) taking out the impregnated and dried catalyst, grinding the impregnated and dried catalyst into uniform fine particles, putting the particles into a vertical tubular furnace, loading quartz wool on a catalyst bed layer, introducing nitrogen at a flow rate of 60mL/min, heating at a temperature rise rate of 5 ℃/min, raising the temperature from room temperature to 400 ℃, calcining at 400 ℃ in a nitrogen atmosphere of 60mL/min for 5h, cooling to 250 ℃, reducing with hydrogen at a rate of 40mL/min for 1h, cooling to room temperature, and taking out to obtain a 5% wt Pt/MWNT catalyst;
(6) the liquid phase ring opening of the 2-MF is carried out in a reaction kettle provided with a heat conduction detector; adding 50mg of 5% wt Pt/MWNT catalyst, 4mmol of 2-methylfuran and 8mL of isopropanol into a reaction kettle, purging the reactor for 3 times by using hydrogen to remove air in the reactor before reaction, and then filling 1MP of hydrogen pressure, keeping the temperature at 25 ℃ and reacting for 3 hours;
(7) after the reaction, the catalyst and the reaction solution were separated by centrifugation.
4. The process for the preparation of pentanol from 2-methylfuran at room temperature using a supported catalyst according to claim 1, wherein: the liquid phase ring opening of the 2-MF in the step (6) is carried out in a reaction kettle provided with a heat conduction detector; to the reaction kettle was added 50mg of 5% wt Pt/MWNT catalyst, 4mmol 2-MF and 8mL isopropanol, and an amount of dodecane was added as an internal standard.
5. The process for the preparation of pentanol from 2-methylfuran at room temperature using a supported catalyst according to claim 1, wherein: after the reaction in the step (7), centrifugally separating the catalyst from the reaction solution; the catalyst powder was filtered off and the reaction results were analyzed by gas chromatography, GC; the recovered catalyst filtrate was continuously washed with isopropanol and then dried overnight in a vacuum oven at 60 ℃.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114931938A (en) * 2022-06-15 2022-08-23 南京工业大学 Method for preparing cyclopentanol through catalytic hydrogenation of cyclopentanone by using carbon nanotube outer wall loaded platinum nanoparticle catalyst
CN115466234A (en) * 2022-10-25 2022-12-13 安徽华业香料股份有限公司 Novel preparation method of gamma-heptalactone
CN115850042A (en) * 2022-12-26 2023-03-28 南京工业大学 Method for preparing 2-pentanone by hydrogenation of 2-methylfuran through platinum-based catalyst
CN116239549A (en) * 2023-03-16 2023-06-09 南京工业大学 Method for using platinum-based catalyst in hydrogenation reaction of 2-methylfuran

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TING WANG等: "Selective hydroconversion of 2-methylfuran to pentanols on MWNT-supported Pt catalyst at ambient temperature", 《RARE METALS》 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114931938A (en) * 2022-06-15 2022-08-23 南京工业大学 Method for preparing cyclopentanol through catalytic hydrogenation of cyclopentanone by using carbon nanotube outer wall loaded platinum nanoparticle catalyst
CN115466234A (en) * 2022-10-25 2022-12-13 安徽华业香料股份有限公司 Novel preparation method of gamma-heptalactone
CN115466234B (en) * 2022-10-25 2024-01-30 安徽华业香料股份有限公司 Preparation method of gamma-heptanolide
CN115850042A (en) * 2022-12-26 2023-03-28 南京工业大学 Method for preparing 2-pentanone by hydrogenation of 2-methylfuran through platinum-based catalyst
CN116239549A (en) * 2023-03-16 2023-06-09 南京工业大学 Method for using platinum-based catalyst in hydrogenation reaction of 2-methylfuran
CN116239549B (en) * 2023-03-16 2024-02-20 南京工业大学 Method for using platinum-based catalyst in hydrogenation reaction of 2-methylfuran

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Application publication date: 20211207