A method for efficiently reducing furfural to furfuryl alcohol using Hf-doped ZSM-5 modified molecular sieve

Abstract

The present invention relates to a method for efficiently reducing furfural to furfuryl alcohol by using an Hf-doped ZSM-5 modified molecular sieve, belonging to the technical field of furfuryl alcohol preparation. The preparation process of the catalyst is based on the hydrothermal method. Under alkaline conditions, a large amount of silicon in the ZSM-5 molecular sieve structure is dissolved. At the same time, the added Hf + partially forms HfO2 by polycondensation reaction and deposits on the catalyst surface, and part of it fills the vacancies formed after the dissolution of silicon in the ZSM-5 structure, finally forming a catalyst Hf@ZSM-5 with a special structure and excellent catalytic effect. The catalyst uses isopropanol as the hydrogen source and organic solvent, and realizes the reduction of furfural to furfuryl alcohol through catalytic transfer hydrogenation. After optimizing the reaction conditions, a conversion rate of 100% and a yield of 99% are finally achieved under the conditions of 1 h and 160 °C. At the same time, the catalyst has high recycling stability and can still reach a conversion rate of more than 90% after three reactions.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and further belongs to the technical field of furfuryl alcohol preparation, and specifically relates to a method for efficiently reducing furfural to furfuryl alcohol by using a Hf-doped ZSM-5 modified molecular sieve. Background Art

[0002] Based on the energy crisis and environmental problems caused by fossil fuels, the search for a green and renewable new energy source has become a hot topic in current research. Among many renewable resources, biomass resources are considered to be a fossil fuel substitute with great potential due to their high reserves and the fact that they are the only renewable carbon source in nature. Therefore, they have become the focus of global renewable energy research. Furfural, as one of the most promising derivatives of biomass resources, can continue to generate many chemicals needed for the development of human society using it as a substrate. Among them, furfural alcohol is undoubtedly the most important product. According to statistics, 65%-70% of the furfural produced worldwide each year is directly converted into furfural alcohol through hydrogenation.

[0003] Using organic alcohol as hydrogen donor to catalyze furfural to furfuryl alcohol through catalytic transfer hydrogenation (CTH) is a safer and more economical approach than using hydrogen and formic acid as hydrogen sources. It not only avoids the loss of formic acid to equipment, but also has higher safety performance than hydrogen, so it has received more attention. Qi Haisong et al. prepared a non-precious metal-loaded nitrogen-doped carbon catalyst in publication number CN111087370A, which can achieve a conversion rate of 99% and a yield of 98% furfuryl alcohol at 160°C for 3h. Li Feng et al. prepared a phosphorus-modified catalyst in publication number CN111036301A, which can catalyze furfural to furfuryl alcohol at 180°C for 5h to obtain a conversion rate of 97.2% and a yield of 99.2%. Although these catalysts can achieve good results after optimizing the conditions, the preparation process of the catalyst is complicated and the hydrogenation reaction time is relatively long. The present invention utilizes a hydrothermal method to modify the ZSM-5 molecular sieve under alkaline conditions and at the same time incorporates Hf therein, which not only has a simple catalyst preparation method, but also the final Hf@ZSM-5 catalyst can achieve a furfural conversion rate of 100% and a furfuryl alcohol yield of 99% under the conditions of 1h and 160°C, and has stronger market competitiveness. Summary of the invention

[0004] The object of the present invention is to provide a method for efficiently reducing furfural to furfuryl alcohol by using a Hf-doped ZSM-5 modified molecular sieve.

[0005] The object of the present invention is achieved in this way. The method for efficiently reducing furfural to furfuryl alcohol by using the Hf-doped ZSM-5 modified molecular sieve is that a catalyst Hf@ZSM-5 with a special structure is added to the raw material furfural and the organic solvent isopropanol and placed in a closed high-pressure reactor to obtain the target product furfuryl alcohol through hydrogenation reaction; the preparation of the catalyst Hf@ZSM-5 with a special structure includes hydrothermal reaction and post-treatment steps, specifically including:

[0006] A. Hydrothermal reaction: HfCl4, NaOH solution and ZSM-5 are placed in a hydrothermal kettle, and then the hydrothermal kettle is transferred to an oven for hydrothermal reaction and then filtered to obtain a white precipitate a;

[0007] B. Post-treatment: The white precipitate a is washed alternately with deionized water and ethanol until it becomes neutral, and then dried to obtain the target catalyst Hf@ZSM-5 with a special structure.

[0008] The present invention is based on the hydrothermal method. Under alkaline conditions, HfCl4 solution and molecular sieve ZSM-5 are hydrothermally treated. In this process, a large amount of silicon in the structure of ZSM-5 as aluminosilicate is dissolved, and the original unit cell structure is destroyed. At the same time, the added Hf + A part of it forms HfO2 through condensation reaction and is deposited on the surface of the molecular sieve, and a part of it fills the vacancies of silicon dissolved in the molecular sieve. After the hydrothermal reaction is completed, the catalyst Hf@ZSM-5 with a special structure and excellent catalytic effect is obtained.

[0009] The preparation method of the catalyst specifically comprises the following steps:

[0010] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0011] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0012] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0013] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0014] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0015] The product after washing in (3) is dried at 50° C. for 12 h.

[0016] The reaction temperature is 150-160° C., the hydrogenation reaction time is 1-4 hours, and the liquid product furfuryl alcohol is qualitatively and quantitatively detected by GC-MS and GC.

[0017] Beneficial effects of the present invention:

[0018] 1. The catalyst provided by the present invention adopts a hydrothermal method to achieve the modification of the molecular sieve ZSM-5 and the doping of the active metal Hf under simple and mild process conditions.

[0019] 2. The catalyst Hf@ZSM-5 uses isopropanol as the hydrogen source and reaction solvent, and achieves the reduction of furfural through catalytic transfer hydrogenation, which has higher safety and lower economic cost.

[0020] 3. The catalyst Hf@ZSM-5 has excellent catalytic effect, and can achieve 100% conversion rate and 99% yield under the conditions of 1h and 160℃.

[0021] 4. The catalyst Hf@ZSM-5 has good recovery stability and still has a conversion rate and yield of more than 90% after three reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a diagram of the HfO2 formation mechanism of the present invention;

[0023] Figure 2 It is the infrared spectrum of Hf@ZSM-5 in the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0025] The method for efficiently reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve of the present invention is to add a catalyst Hf@ZSM-5 with a special structure to raw materials furfural and organic solvent isopropanol, place them in a closed high-pressure reactor, and obtain the target product furfuryl alcohol through hydrogenation reaction; the preparation of the catalyst Hf@ZSM-5 with a special structure includes hydrothermal reaction and post-treatment steps, specifically including:

[0026] A. Hydrothermal reaction: HfCl4, NaOH solution and ZSM-5 are placed in a hydrothermal kettle, and then the hydrothermal kettle is transferred to an oven for hydrothermal reaction and then filtered to obtain a white precipitate a;

[0027] B. Post-treatment: The white precipitate a is washed alternately with deionized water and ethanol until it becomes neutral, and then dried to obtain the target catalyst Hf@ZSM-5 with a special structure.

[0028] The temperature of the hydrogenation reaction is 120-180°C.

[0029] The temperature of the hydrogenation reaction is 150-160°C.

[0030] The hydrogenation reaction time is 1 to 5 hours.

[0031] The mass volume ratio of the raw material furfural and the organic solvent isopropanol is (0.2~0.4) g / ml: (10~30); the mass ratio of the raw material furfural and the catalyst Hf@ZSM-5 with a special structure is (2~4): (1~3).

[0032] In step A, the mass ratio of HfCl4, NaOH and ZSM-5 is (1~2):(2~4):(2~4).

[0033] In step A, the hydrothermal reactor is placed at 100-150°C for reaction.

[0034] In step A, the NaOH concentration in the hydrothermal reactor is controlled to be 1.5~2.5 mol / L.

[0035] The drying described in step B is performed at 40-60° C. for 10-15 hours.

[0036] The present invention is further described below with specific implementation cases:

[0037] Example 1

[0038] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0039] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 4 hours.

[0040] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0041] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0042] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0043] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0044] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0045] The product after washing in (3) is dried at 50° C. for 12 h.

[0046] GC-MS and GC were used for qualitative and quantitative detection. In this embodiment, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 100%.

[0047] Example 2

[0048] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0049] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 2 h.

[0050] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0051] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0052] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0053] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0054] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0055] The product after washing in (3) is dried at 50° C. for 12 h.

[0056] GC-MS and GC were used for qualitative and quantitative detection. In this embodiment, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 100%.

[0057] Example 3

[0058] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0059] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0060] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0061] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0062] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0063] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0064] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0065] The product after washing in (3) is dried at 50° C. for 12 h.

[0066] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 99%.

[0067] Example 4

[0068] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0069] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 150°C for 2 hours.

[0070] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0071] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0072] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0073] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0074] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0075] The product after washing in (3) is dried at 50° C. for 12 h.

[0076] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 93.6%, and the yield of furfuryl alcohol was 90.8%.

[0077] Example 5

[0078] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0079] 0.2 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0080] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0081] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0082] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0083] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0084] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0085] The product after washing in (3) is dried at 50° C. for 12 h.

[0086] GC-MS and GC were used for qualitative and quantitative detection. In this embodiment, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 100%.

[0087] Example 6

[0088] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0089] 0.4 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0090] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0091] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0092] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0093] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0094] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0095] The product after washing in (3) is dried at 50° C. for 12 h.

[0096] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 90%, and the yield of furfuryl alcohol was 85.3%.

[0097] Example 7

[0098] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0099] 0.3 g furfural, 10 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0100] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0101] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0102] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0103] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0104] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0105] The product after washing in (3) is dried at 50° C. for 12 h.

[0106] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 70.3%, and the yield of furfuryl alcohol was 68.5%.

[0107] Example 8

[0108] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0109] 0.3 g furfural, 30 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0110] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0111] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0112] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0113] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0114] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0115] The product after washing in (3) is dried at 50° C. for 12 h.

[0116] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 80.5%, and the yield of furfuryl alcohol was 70.9%.

[0117] Example 9

[0118] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0119] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.1 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0120] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0121] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0122] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0123] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0124] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0125] The product after washing in (3) is dried at 50° C. for 12 h.

[0126] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 88.5%, and the yield of furfuryl alcohol was 70%.

[0127] Example 10

[0128] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0129] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.3 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0130] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0131] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0132] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0133] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0134] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0135] The product after washing in (3) is dried at 50° C. for 12 h.

[0136] GC-MS and GC were used for qualitative and quantitative detection. In this embodiment, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 100%.

[0137] Embodiment 11

[0138] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0139] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0140] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0141] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0142] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0143] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0144] The theoretical Hf loading in the hydrothermal reactor in (1) is 25 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0145] The product after washing in (3) is dried at 50° C. for 12 h.

[0146] GC-MS and GC were used for qualitative and quantitative detection. In this embodiment, the conversion rate of furfural was 100%, and the yield of furfuryl alcohol was 100%.

[0147] Example 12

[0148] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0149] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0150] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0151] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0152] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0153] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0154] The theoretical Hf loading in the hydrothermal reactor in (1) is 15 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0155] The product after washing in (3) is dried at 50° C. for 12 h.

[0156] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 88.5%, and the yield of furfuryl alcohol was 84.3%.

[0157] Example 13

[0158] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0159] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0160] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0161] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0162] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0163] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0164] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2.5 mol / L, and the mass of ZSM-5 is 1.0 g.

[0165] The product after washing in (3) is dried at 50° C. for 12 h.

[0166] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 80.1%, and the yield of furfuryl alcohol was 78.3%.

[0167] Embodiment 14

[0168] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0169] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0170] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0171] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0172] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0173] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0174] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 2.0 g.

[0175] The product after washing in (3) is dried at 50° C. for 12 h.

[0176] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 70.5%, and the yield of furfuryl alcohol was 64.3%.

[0177] Embodiment 15

[0178] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0179] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0180] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0181] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0182] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0183] The hydrothermal reactor in (1) is placed at 100° C. for reaction.

[0184] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0185] The product after washing in (3) is dried at 50° C. for 12 h.

[0186] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 80.5%, and the yield of furfuryl alcohol was 74.3%.

[0187] Example 16

[0188] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0189] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0190] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0191] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0192] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0193] The hydrothermal reactor in (1) is placed at 150° C. for reaction.

[0194] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0195] The product after washing in (3) is dried at 50° C. for 12 h.

[0196] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 75.5%, and the yield of furfuryl alcohol was 74.3%.

[0197] Embodiment 17

[0198] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0199] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0200] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0201] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0202] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0203] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0204] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0205] The product after washing in (3) is dried at 60° C. for 12 h.

[0206] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 93.2%, and the yield of furfuryl alcohol was 90%.

[0207] Embodiment 18

[0208] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0209] 0.3 g furfural, 20 mL organic solvent isopropanol and 0.2 g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction at 160°C for 1 h.

[0210] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0211] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0212] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0213] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0214] The theoretical Hf loading in the hydrothermal reactor in (1) is 20 wt %, the NaOH concentration is 2 mol / L, and the mass of ZSM-5 is 1.0 g.

[0215] The product after washing in (3) is dried at 40° C. for 12 h.

[0216] GC-MS and GC were used for qualitative and quantitative detection. In this example, the conversion rate of furfural was 98.2%, and the yield of furfuryl alcohol was 95%.

[0217] Embodiment 19

[0218] A method for efficiently reducing furfural to furfuryl alcohol using a Hf-doped ZSM-5 modified molecular sieve, the specific steps are as follows:

[0219] 0.3g furfural, 20mL organic solvent isopropanol and 0.2g catalyst Hf@ZSM-5 were mixed and added into a closed autoclave, and the target product furfuryl alcohol was obtained after hydrogenation reaction. The hydrogenation reaction conditions were 160℃, 1h. After the reaction, the catalyst was collected, washed with deionized water and anhydrous ethanol 3 times, dried at 50℃ for 12h, and directly used for the next catalytic reaction. The catalytic conditions were: 0.3g furfural, 20mL organic solvent isopropanol and 0.2g catalyst Hf@ZSM-5 (recovered), heated to 160℃, and reacted for 1h.

[0220] (1) Add HfCl4, NaOH solution and ZSM-5 into a 25 mL polytetrafluoroethylene high-pressure hydrothermal reactor, and then transfer the reactor to an oven for hydrothermal reaction for 24 h;

[0221] (2) Wash the obtained white precipitate with deionized water and ethanol alternately until it becomes neutral;

[0222] (3) The washed product is then dried to obtain the catalyst Hf@ZSM-5.

[0223] The hydrothermal reactor in (1) is placed at 120° C. for reaction.

[0224] The NaOH concentration in the hydrothermal reactor in (1) is 2 mol / L.

[0225] The product after washing in (3) is dried at 50° C. for 12 h.

[0226] GC-MS and GC were used for qualitative and quantitative detection. After the catalyst was recycled, the conversion rate of furfural was 90%, and the yield of furfuryl alcohol was 84.3%.

[0227] In summary, the catalyst Hf@ZSM-5 provided by the present invention is prepared by a hydrothermal method, and the synthesis route is short and the process is simple. The catalyst uses isopropanol as a hydrogen source and a reaction solvent, and achieves a 100% furfural conversion rate and a 99% furfuryl alcohol yield under the conditions of 1h and 160°C through catalytic transfer hydrogenation. At the same time, the catalyst has good stability and can still achieve a conversion rate of more than 90% after repeated use.

[0228] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and describes these embodiments in detail in order to better explain the specification.

Claims

1. A method for reducing furfural to furfuryl alcohol by using a Hf-doped ZSM-5 modified molecular sieve, characterized in that: The method for reducing furfural to furfuryl alcohol by using the Hf-doped ZSM-5 modified molecular sieve is that a catalyst Hf@ZSM-5 with a special structure is added to the raw material furfural and the organic solvent isopropanol, and the mixture is placed in a closed high-pressure reactor, and the target product furfuryl alcohol is obtained by hydrogenation reaction; The preparation of the catalyst Hf@ZSM-5 having a special structure includes hydrothermal reaction and post-treatment steps, specifically including: A. Hydrothermal reaction: HfCl4, NaOH solution and ZSM-5 are placed in a hydrothermal kettle, and then the hydrothermal kettle is transferred to an oven for hydrothermal reaction and then filtered to obtain a white precipitate a; B. Post-treatment: The white precipitate a is washed alternately with deionized water and ethanol until it becomes neutral, and then dried to obtain the target catalyst Hf@ZSM-5 with a special structure.

2. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: The temperature of the hydrogenation reaction is 120-180°C.

3. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1 or 2, characterized in that: The temperature of the hydrogenation reaction is 150-160°C.

4. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: The hydrogenation reaction time is 1 to 5 hours.

5. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: The mass volume ratio of the raw material furfural and the organic solvent isopropanol is (0.2~0.4) g / ml: (10~30); the mass ratio of the raw material furfural and the catalyst Hf@ZSM-5 with a special structure is (2~4): (1~3).

6. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: In step A, the mass ratio of HfCl4, NaOH and ZSM-5 is (1~2):(2~4):(2~4).

7. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: In step A, the hydrothermal reactor is placed at 100-150°C for reaction.

8. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: In step A, the NaOH concentration in the hydrothermal reactor is controlled to be 1.5~2.5 mol / L.

9. The method for reducing furfural to furfuryl alcohol by using Hf-doped ZSM-5 modified molecular sieve according to claim 1, characterized in that: The drying described in step B is performed at 40-60° C. for 10-15 hours.

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