A coordination zirconium phosphotungstate catalyst and its application in catalytic hydrogenation of furfural

Abstract

The invention discloses a coordination type zirconium phosphotungstate catalyst and its application in catalytic hydrogenation of furfural, belonging to the field of heterogeneous catalysis. The zirconium phosphotungstate catalyst prepared by the invention not only has good catalytic effect on the conversion of furfural to furfuryl alcohol, but also has mild reaction conditions. The yield of solid line furfuryl alcohol can be 98% if it can be reacted for 1 h at 120 C., and the amount of catalyst is less, which greatly reduces the energy consumption in the prior art. In addition, the zirconium phosphotungstate prepared by the invention is easy to separate, has good stability for catalyzing the hydrogenation of furfural to furfuryl alcohol, and is a new, efficient and green catalyst.

Claims

1. method of making a coordination type zirconium phosphotungstate catalyst comprising: dissolving phosphotungstic acid and ZrCl.sub.4 in DMF respectively to obtain phosphotungstic acid solution and ZrCl.sub.4 solution; after ultrasonic treatment, adding phosphotungstic acid solution drop by drop into ZrCl.sub.4 solution within 5-30 min; after uniform mixing, adding triethylamine; then reacting at room temperature for 3-6 hours; aging more than 4 hours; washing for 1-3 times with DMF, methanol, and anhydrous ether respectively; and drying in vacuum at 70-100 C. for more than 8 hours.

2. The according to claim 1, wherein the molar ratio of the phosphotungstate and ZrCl.sub.4 is 3:11:3.

3. The method according to claim 1 the concentration of the phosphotungstate solution is (0.05-0.15) mol/L, and the concentration of the ZrCl.sub.4 solution is (0.05-0.15) mol/L.

4. The method according to claim 1 the ultrasonic treatment time is 5 to 30 minutes.

5. A coordination type zirconium phosphotungstate catalyst prepared by the method according claim 1.

6. A method for preparing furfuryl alcohol by catalytic hydrogenation of furfural comprising hydrogenating the furfural in presence of the coordination zirconium phosphotungstate of claim 5 as a catalyst.

7. The method according to claim 6, wherein the hydrogenating is conducted in presence of isopropanol in an amount of 5-10 ml/mmol furfural as a hydrogen source.

8. The method according to claim 7, wherein the amount of isopropane is 5 ml/mmol furfural.

9. The method of claim 6 wherein the hydrogenating is conducted at a temperature of 120 C.

10. The method of claim 6 wherein hydrogenating is conducted for 1 hour.

11. The method of claim 6 further comprising converting the furfuryl alcohol to resin, fuel, synthetic fiber, rubber, plastic, or pesticide.

12. The method of claim 6 wherein the hydrogenating is conducted in presence of 0.01-0.03 g coordination zirconium phosphotungstate/mmol furfural as the catalyst at 110-150 C. for 0.5-4 hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is the XRD diagram of the coordination zirconium phosphotungstate catalyst prepared in example 1.

[0026] FIG. 2 is the SEM (left) and TEM (right) photos of the coordination zirconium phosphotungstate catalyst prepared in example 1.

[0027] FIG. 3 shows the furfuryl alcohol yield of Furfural Hydrogenation Catalyzed by different types of zirconium phosphotungstate catalysts in example 4.

[0028] FIG. 4 shows the furfuryl alcohol yield of the coordinated zirconium phosphotungstate catalyst in example 5 under different temperatures.

[0029] FIG. 5 shows the furfuryl alcohol yield of the coordinated zirconium phosphotungstate catalyst in example 6 under different time.

[0030] FIG. 6 shows the furfuryl alcohol yield of the coordinated zirconium phosphotungstate catalyst in Example 7 under different catalyst dosage.

[0031] FIG. 7 shows the furfuryl alcohol yield of the coordinated zirconium phosphotungstate catalyst in example 8 under different reaction solvents.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] Determination of furfural by gas chromatography (GC): calculate the ratio of peak area of furfural (FF) and furfuryl alcohol (FA), with naphthalene as reference sample.

[0033] Calculation formula of conversion rate:

[00001]$\begin{array}{cc}F.Math..Math.F.Math..Math.\mathrm{conversion}.Math..Math.\left(\mathrm{mol}.Math..Math.\%\right)=\left(1-\frac{\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.F.Math..Math.F}{\mathrm{initial}.Math..Math.\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.F.Math..Math.F}\right)100.Math.\%.& \left(1\right)\end{array}$

[0034] Calculation formula of yield:

[00002]$\begin{array}{cc}\mathrm{Yield}.Math..Math.\mathrm{of}.Math..Math.F.Math..Math.A.Math..Math.\left(\mathrm{mol}.Math..Math.\%\right)=\left(\frac{\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.F.Math..Math.A}{\mathrm{initial}.Math..Math.\mathrm{moles}.Math..Math.\mathrm{of}.Math..Math.F.Math..Math.F}\right)100.Math.\%.& \left(2\right)\end{array}$

[0035] The invention will be further described in combination with embodiments, but the embodiments of the invention are not limited to this.

EXAMPLE 1

[0036] (1) Pretreatment of raw materials: the phosphotungstic acid containing crystal water is dried in vacuum at 100 C. for 10h, and then it is ground into powder in a mortar.

[0037] (2) Preparation of zirconium phosphotungstate (ZrPW): take 2.88 g of the pretreated phosphotungstic acid, dissolve it in DMF, the concentration of phosphotungstic acid is 0.05 mol/l, and treat it in ultrasonic for 20 min, then take 0.466 g of ZrCl.sub.4, dissolve it in DMF, the concentration of ZrCl.sub.4 is 0.1 mol/l, and treat it in ultrasonic for 20 min. Put the ultrasonic treated ZrCl.sub.4 solution into a round bottom flask and add the ultrasonic treated phosphotungstic acid solution drop by drop within 30 minutes. After the above solution is uniformly mixed, add 3 ml triethylamine solution drop by drop, react at room temperature for 4 h, age for 4 h, wash with DMF, methanol and anhydrous ether for three times respectively, dry in vacuum at 80 C. for 12 h, and grind it to powder to prepare zirconium phosphotungstate (ZrPW).

[0038] The prepared zirconium phosphotungstate (ZrPW) is characterized by its XRD and electron micrographs as shown in FIG. 1 and FIG. 2, respectively. It can be seen that the catalyst prepared by the invention is an irregular mesoporous structure.

EXAMPLE 2

[0039] (1) Pretreatment of raw materials: the phosphotungstic acid containing crystal water is dried in vacuum at 100 C. for 10 h, and then it is ground into powder in a mortar.

[0040] (2) Preparation of zirconium phosphotungstate (ZrPW): take 2.88 g of the pretreated phosphotungstic acid and dissolve it in DMF, the concentration of phosphotungstic acid is 0.10 mol/l, and then deal with it in ultrasonic for 15 min, then take 0.466 g of ZrCl.sub.4 and dissolve it in DMF, the concentration of ZrCl.sub.4 is 0.10 mol/l, and deal with it in ultrasonic for 20 min. Put the ultrasonic treated ZrCl.sub.4 solution into a round bottom flask and add the ultrasonic treated phosphotungstic acid solution drop by drop within 20 minutes. After the above solution is evenly mixed, add 3 ml triethylamine solution drop by drop, react at room temperature for 3 h, age for 5 h, wash with DMF, methanol and anhydrous ether for three times respectively, dry in vacuum at 100 C. for 10 h, grind it to powder to prepare zirconium phosphotungstate (ZrPW).

EXAMPLE 3

[0041] (1) Pretreatment of raw materials: the phosphotungstic acid containing crystal water is dried in vacuum at 100 C. for 10 h, and then it is ground into powder in a mortar.

[0042] (2) Preparation and catalytic performance of zirconium phosphotungstate (ZrPW) with different ratio: ZrCl.sub.4: PW (phosphotungstic acid) with the molar ratio of 3:1, 2:1, 1:1, 1:2 and 1:3 was used to synthesize zirconium phosphotungstate. The two raw materials were respectively dissolved in 20 ml DMF and treated with ultrasonic for 20 min. After the above solution is evenly mixed, add 3 ml triethylamine solution drop by drop, react at room temperature for 4 h, age for 4 h, wash with DMF, methanol and anhydrous ether for three times respectively, dry in vacuum at 80 C. for 12 h, grind it to powder to prepare zirconium phosphotungstate catalyst.

[0043] The prepared zirconium phosphotungstate catalyst was used as the catalyst for furfural:

[0044] (1) Weigh 200 mg of the above catalyst into 20 ml of polytetrafluoroethylene lining respectively, add quantitative naphthalene (here naphthalene as reference sample, the same below) and 5 ml of isopropanol;

[0045] (2) Weigh 0.1 mol furfural and add it into the system in step (1), put the PTFE lining into the stainless steel reactor, heat it to 150 C. under magnetic stirring, and react for 3 hours. After the reactor cools to room temperature, use the centrifuge to separate the solid and liquid, and take the liquid phase test sample;

[0046] (3) Transfer 50 L of reaction solution in step (2) with a pipette gun, and determine the yield of furfuryl alcohol with a liquid chromatograph.

TABLE-US-00001 TABLE 1 catalytic performance of zirconium phosphotungstate catalysts with different proportions proportion 3:1 2:1 1:1 1:2 1:3 C.sub.FF 100 92.3 90.03 100 99.14 Y.sub.FA 35 58.37 40.24 39.86 42.22

[0047] It can be seen that zirconium phosphotungstate prepared by ZrCl.sub.4: PW (phosphotungstic acid) with the molar ratio of 2:1 is selected as the catalyst for further study.

EXAMPLE 4

[0048] According to the method of example 1, ZrCl.sub.4 is replaced with AlCl.sub.3 to prepare the corresponding catalyst aluminum phosphotungstate (AlPW); in addition, according to the method of example 1, the catalyst phosphotungstic acid and ZrCl.sub.4 are separately prepared with phosphotungstic acid and ZrCl.sub.4 as reaction raw materials.

[0049] According to the method of example 1, phosphotungstic acid is replaced by phosphomolybdic acid (PM), which is reacted with ZrCl.sub.4 and AlCl.sub.3 respectively to prepare corresponding catalysts zirconium phosphomolybdate (ZrPM) and aluminum phosphomolybdate (AlPM). In addition, the catalyst phosphomolybdic acid is separately prepared with phosphomolybdic acid according to the method of example 1.

[0050] The catalyst ZrPW prepared in example 1 and the catalyst AlPW, phosphotungstic acid, ZrCl.sub.4, zirconium phosphomolybdate ZrPM, aluminum phosphomolybdate AlPM or phosphomolybdate PM prepared in example 4 were used as catalysts for furfural respectively

[0051] (1) Weigh 200 mg of the above catalysts (ZrPW, AlPW, phosphotungstic acid, ZrCl.sub.4, ZrPM, AlPM or PM) respectively into 20 ml of polytetrafluoroethylene lining, add quantitative naphthalene (here naphthalene as reference sample, the same below) and 5 ml of isopropanol;

[0052] (2) Weigh 0.1 mol furfural and add it into the system in step (1), put the PTFE lining into the stainless steel reactor, heat it to 120 C. under magnetic stirring, and react for 1 h. After the reactor cools to room temperature, use the centrifuge to separate the solid and liquid, and take the liquid phase test sample;

[0053] (3) Transfer 50 L of reaction solution in step (2) with a pipette gun, and determine the yield of furfuryl alcohol with a liquid chromatograph.

[0054] According to the determination, the results are as shown in FIG. 3. The catalysts prepared from ZrPM, PM, PW, ZrCl.sub.4, AlPW, AlPM or ZrPW are used to catalyze the hydrogenation of furfural. The yields of furfural are 31.56%, 0.32%, 0.81%, 3.26%, 5.11%, 0% and 98.64% respectively. It can be seen that only Zr PW catalyst has good catalytic performance for furfural production.

EXAMPLE 5

[0055] (1) Weigh 200 mg of coordination zirconium phosphotungstate prepared in example 1 into 20 ml of polytetrafluoroethylene lining, and add quantitative naphthalene and 5 ml of isopropanol;

[0056] (2)Weigh 0.1 mol furfural and add it into the reaction system of step (1), put the PTFE lining into the stainless steel reactor, heat it to 110 C.150 C. under magnetic stirring, and react for 1H. After the reaction is finished, after the reactor cools to room temperature, separate the solid and liquid with centrifuge, and take the liquid phase test sample;

[0057] (3) Transfer 50 L of reaction solution in step (2) with a pipette gun, and determine the yield of furfuryl alcohol with a liquid chromatograph.

[0058] As shown in FIG. 4, when the reaction temperature is 110 C., 120 C., 130 C., 140 C. and 150 C., the yield of furfuryl alcohol is 46.24%, 98.64%, 92.89%, 92.86% and 80.41%, respectively. It can be seen that the coordination type zirconium phosphotungstate catalyst prepared by the invention can achieve a high yield of furfuryl alcohol at 120 C. and react for 1 h.

EXAMPLE 6

[0059] (1) Weigh 200 mg of the coordination type zirconium phosphotungstate catalyst prepared in example 1 into 20 ml of polytetrafluoroethylene lining, and add quantitative naphthalene and 5 ml of isopropanol;

[0060] (2)Weigh 0.1 mol furfural and add it into the reaction system of step (1), put the PTFE lining into the stainless steel reaction kettle, heat it to 120 C. under magnetic stirring, react for 0.5-4 h, the reaction is finished, after the reaction kettle is cooled to room temperature, separate the solid and liquid with centrifuge, take the liquid phase as the sample to be tested;

[0061] (3) The reaction solution in step (2) of 50 L was transferred with a pipette gun and the yield of furfuryl alcohol was determined by gas chromatography.

[0062] As shown in FIG. 5, the yield of furfuryl alcohol is 52.82%, 98.64%, 96.72%, 92.67% and 91.38% when the reaction time is 0.5 h, 1 h, 2 h, 3 h and 4 h respectively. It can be seen that with the increase of reaction time, the yield of furfuryl alcohol increases gradually, and then decreases.

EXAMPLE 7

[0063] (1) Weigh 100 mg, 150 mg, 200 mg, 250 mg or 300 mg of the coordination type zirconium phosphotungstate catalyst prepared in example 1 respectively into 20 ml of polytetrafluoroethylene lining, and add quantitative naphthalene and 20 ml of isopropanol;

[0064] (2)Weigh 0.1mol furfural and add it into the reaction system of step (1), put the PTFE lining into the stainless steel reactor, heat it to 120 C. under magnetic stirring, react for 1 h, after the reactor cools to room temperature, use the centrifuge to separate the solid and liquid, take the liquid as the sample to be tested;

[0065] (3) The reaction solution in step (2) of 50 L was transferred with a pipette gun and the yield of furfuryl alcohol was determined by gas chromatography.

[0066] As shown in FIG. 6, when the amount of catalyst is 100 mg, 150 mg, 200 mg, 250 mg and 300 mg respectively, the yield of furfuryl alcohol is 87.76%, 92.61%, 98.64%, 93.52% and 93.52% respectively.

EXAMPLE 8

[0067] (1) Weigh 200 mg of the coordination type zirconium phosphotungstate catalyst prepared in example 1 into 20 ml of polytetrafluoroethylene lining, add quantitative naphthalene, respectively add solvent methanol, ethanol, n-pentanol, n-butanol, 2-butanol and t-butanol;

[0068] (2)Weigh 0.1mol furfural and add it into the reaction system of step (1), put the PTFE lining into the stainless steel reactor, heat it to 120 C. under magnetic stirring, and react for 1H. After the reactor cools to room temperature, use the centrifuge to separate the solid and liquid, and take the liquid as the sample to be tested;

[0069] (3) The reaction solution in step (2) of 50 L was transferred with a pipette gun and the yield of furfuryl alcohol was determined by gas chromatography.

[0070] As shown in FIG. 7, when the reaction solvent is methanol, ethanol, n-pentanol, n-butanol, 2-butanol and tert butanol, the yield of furfuryl alcohol is 0%, 21.08%, 23.75%, 33.75%, 31.35% and 0%, respectively.

EXAMPLE 9

[0071] (1) Weigh 200 mg of the coordination type zirconium phosphotungstate catalyst prepared in example 1 into 20 ml of polytetrafluoroethylene lining, and add quantitative naphthalene and 5 ml of isopropanol;

[0072] (2)Weigh 0.1mol furfural and add it into the reaction system of step (1), put the PTFE lining into the stainless steel reactor, heat it to 120 C. under magnetic stirring, and react for 1H. After the reactor cools to room temperature, use the centrifuge to separate the solid and liquid, and take the liquid phase as the sample to be tested;

[0073] (3) The reaction solution in step (2) of 50 L was transferred with a pipette gun and the yield of furfuryl alcohol was determined by gas chromatography.

[0074] After the reaction, clean and dry the filtered catalyst, and then put it into the above catalytic reaction for recycling. The results show that the yield of furfuryl alcohol is still as high as 82.44% after 6 cycles of use of coordination zirconium phosphotungstate.

[0075] Although the invention has been disclosed as above in a preferred embodiment, it is not used to define the invention. Anyone familiar with the technology can make various changes and modifications within the spirit and scope of the invention. Therefore, the scope of protection of invention shall be subject to that defined in the claims.