A catalyst for converting sorbitol to light alkanes, its preparation method and use

Abstract

The application discloses a catalyst for converting sorbitol into light alkane and a preparation method thereof. The catalyst takes non-noble metal nickel as an active component, SiO2 sol as a carrier, and boron oxide is doped in the obtained nickel-based catalyst. By adjusting the addition amount of boron oxide, the catalyst with uniform nanoflower structure is obtained. The application dopes boron oxide in the non-noble metal nickel-based catalyst, improves the activity and selectivity of the catalyst, and further obtains a catalyst with low cost, good catalytic activity and cyclic thermal stability. Further, the catalyst is applied to the technical field of converting sorbitol into light alkane, can realize a total carbon yield of more than 90%, and efficiently converts sorbitol into light alkane through a hydrodeoxygenation reaction, opens up a new road for efficient utilization and green development of biomass resources, and obtains a method with low energy consumption, low equipment requirement and simple and easy-to-control process.

Description

Technical Field

[0001] This invention relates to a catalyst, its preparation method, and its application, specifically to a catalyst for converting sorbitol into light alkanes, its preparation method, and its application. Background Technology

[0002] Light alkanes (such as C1-C6 alkanes) are an important class of organic compounds with wide applications in automotive fuels, biopharmaceutical intermediates, and organic solvents. Sorbitol is a renewable biomass platform compound that can be produced on a large scale through the catalytic hydrogenation of glucose solutions obtained from starch and cellulose hydrolysis. It is also one of the main end products of photosynthetic carbon fixation. Sorbitol-derived renewable biofuels have the potential to meet the world's green energy needs and achieve carbon neutrality. Therefore, developing a method for converting sorbitol into light alkanes can not only achieve high-value utilization of biomass but also provide clean alternatives to petrochemical resources, which has significant theoretical and practical value for solving energy and environmental problems.

[0003] Existing research mainly focuses on the development of noble metal-based bifunctional catalysts, utilizing the synergistic effect of their metal centers and solid acidic supports to achieve selective hydrodeoxygenation of sorbitol to prepare light alkanes. For example, invention applications CN105597752B and CN114605214A disclose Ru-supported carbon materials and molybdenum carbide materials, respectively, for improving the selective hydrodeoxygenation of sorbitol to prepare C5 and C6 alkanes. In their work, Yong Tae Kim et al. achieved yields of 66.8% and 44.4% of gasoline series products (C5-C6 alkanes, C2-C6 alcohols, etc.) of sorbitol under aqueous phase conditions using bifunctional catalysts Pt / Zr-P and Pt-ReOx / C, respectively.

[0004] However, the scarcity and high cost of precious metal-based catalysts limit their widespread industrial application. Therefore, designing efficient and inexpensive non-precious metal-based catalysts is essential. However, the activity and stability of non-precious metal-based catalysts are generally lower than those of precious metal-based catalysts, and they require more stringent reaction conditions, resulting in limited reports. Invention application CN102389832B discloses a non-precious metal nickel-supported HZSM-5 and MCM-41 composite molecular sieve catalyst, achieving a maximum yield of 74.8% for the conversion of sorbitol to light alkanes (C1-C6). However, under hydrothermal conditions, the insufficient hydrothermal stability of the silica-alumina oxide molecular sieve and the loss of aluminum lead to a decrease in catalyst stability. This situation poses a significant challenge to catalyst development and application. Therefore, there is an urgent need for a low-cost catalyst with good catalytic performance for the conversion of sorbitol to light alkanes. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a catalyst for converting sorbitol into light alkanes, its preparation method, and its application. Based on the non-precious metal nickel, boron oxide is doped into the nickel-based catalyst to improve its activity and selectivity. This results in a low-cost catalyst with good catalytic activity and cycling thermal stability.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] A catalyst for converting sorbitol into light alkanes is provided, using non-precious metal nickel as the active component and SiO2 sol as the support. Boron oxide is doped into the nickel-based catalyst obtained by the two components, and by controlling the amount of boron oxide added, a catalyst with a uniform nanoflower-like structure is obtained.

[0008] The method for preparing the catalyst for converting sorbitol to light alkanes as described above includes the following steps:

[0009] (1) Mix active metal nickel and boron oxide with ammonia water, stir vigorously and thoroughly, and add SiO2 sol;

[0010] (2) The ammonia was evaporated by water bath heating and heated to pH 6-8. The mixture was then filtered by vacuum pump. The upper green solid was washed, dried overnight, and calcined in air to obtain a black catalyst precursor.

[0011] (3) The black catalyst precursor obtained in step (2) is reduced under a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes; in the catalyst for converting sorbitol into light alkanes, the amount of boron oxide doping is 1-10 wt% (preferably 5 wt%), the loading of active metal nickel is 20-50 wt%, and the mass percentage of silicon is 5-35 wt%.

[0012] Preferably, the amount of ammonia added in step (1) is 10 mL; the amount of SiO2 sol added is 5 g.

[0013] Preferably, the active nickel component selected in step (1) is nickel salt Ni(NO3)2·6H2O, the boron oxide is B2O3, and the amount of nickel salt Ni(NO3)2·6H2O and the amount of B2O3 added is in a mass ratio of 400:1 to 40:1.

[0014] Preferably, the ammonia water in step (1) is ammonia water with an ammonia (NH3) content of 25-28 wt%; the SiO2 sol is SiO2 sol with a SiO2 content of 40 wt%.

[0015] Preferably, the water bath heating temperature in step (2) is 80°C; the roasting is 550-600°C for 3 hours.

[0016] Preferably, the reducing atmosphere in step (3) is 5% hydrogen (H2) and 95% argon (Ar) by volume, the reducing temperature is 600 °C, and the reducing time is 1 h.

[0017] The catalysts used above for converting sorbitol to light alkanes are used in applications where sorbitol is catalytically converted to light alkanes.

[0018] The application described above includes the following operational steps:

[0019] (i) Place sorbitol, the catalyst for converting sorbitol to light alkanes, and the solvent in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times; the mass ratio of the catalyst for converting sorbitol to light alkanes to sorbitol is 1:2 to 1:20.

[0020] (ii) Introduce H2 and maintain the reaction at 250-310 °C for 0.5-10 h;

[0021] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid after the reaction, from which the catalyst is removed, is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed using GC-MS, gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC).

[0022] Preferably, the amount of sorbitol added in step (i) is 1-50% of the solvent mass, and the solvent is tetradecane or decahydronaphthalene.

[0023] Preferably, the pressure of H2 introduced in step (ii) is 3-8 MPa.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] This invention dops boron oxide into a non-precious metal nickel-based catalyst to improve its activity and selectivity, thereby obtaining a low-cost catalyst with good catalytic activity and cyclic thermal stability. Furthermore, when applied to the field of sorbitol to light alkanes, this catalyst can achieve a total carbon yield of over 90%, efficiently converting sorbitol into light alkanes via hydrodeoxygenation. This opens up new avenues for the efficient utilization and green development of biomass resources, providing a method with low energy consumption, low equipment requirements, and a simple and easily controllable process. Attached Figure Description

[0026] Figure 1The figures are XRD patterns before and after boron oxide doping; curve i is the XRD pattern of the catalyst prepared in Example 1 of this invention for converting sorbitol into light alkanes, and curve ii is the XRD pattern of the NiSi-PS-1 catalyst.

[0027] Figure 2 This is a SEM image of the NiSi-PS-1 catalyst.

[0028] Figure 3 This is a SEM image of the catalyst prepared in Example 1 of the present invention for converting sorbitol into light alkanes.

[0029] Figure 4 The gas-phase qualitative results of the product in Application Example 8 of this invention are shown. Detailed Implementation

[0030] The specific embodiments are described in detail below with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the examples are commercially available. The boron doping amount in the examples was obtained after the prepared catalyst was tested on the scientific research instrument testing platform.

[0031] In this invention, the XRD testing method is as follows: detection and analysis are performed using a MiniFlex 600 X-ray diffractometer from Rigaku Corporation of Japan; operating voltage 40 kV, scanning range 2θ = 5 ~ 80°, Cu Kα target: λ = 0.154 nm, scanning speed 15° / min.

[0032] The ammonia solution used in the examples was ammonia solution containing 25-28% ammonia (NH3) by mass, produced by Guangdong Guanghua Science & Technology Co., Ltd. (analytical grade); the nickel nitrate hexahydrate (Ni(NO3)2·6H2O) was also produced by Guangdong Guanghua Science & Technology Co., Ltd. (analytical grade). Boron oxide (B2O3) was 98% boron oxide, 40-60 mesh, produced by Shanghai Maclean Biochemical Technology Co., Ltd. The SiO2 sol was a SiO2 sol with a SiO2 content of 40wt% (produced by Sigma-Aldrich).

[0033] Example 1

[0034] A method for preparing a catalyst for converting sorbitol to light alkanes, comprising the following steps:

[0035] (1) Mix 5.57g of active metal nickel Ni(NO3)2·6H2O and 0.075g of boron oxide B2O3 with 10 mL of ammonia water, stir vigorously, add 5g of SiO2 sol with a mass percentage of 40%, stir thoroughly, and obtain a light blue suspension.

[0036] (2) The light blue suspension obtained in step (1) was heated to 80°C and subjected to a water bath to evaporate ammonia. The suspension was heated to pH 6-8, filtered by vacuum pump, and the upper green solid was washed 4 times with deionized water. It was dried at 80°C overnight and calcined at 600°C in air for 3 h to obtain a black catalyst precursor.

[0037] (3) The black catalyst precursor obtained in step (2) is reduced at 600 °C for 1 h in a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes; the reducing atmosphere is a mixture of 5% H2 and 95% Ar; in the catalyst obtained after the reaction for converting sorbitol into light alkanes, the loading of active metal nickel is approximately 35 wt%, the doping amount of boron is 0.67 wt%, and the mass percentage of silicon is approximately 20 wt%. The boron oxide doping amount is 5 wt%.

[0038] Example 2

[0039] A method for preparing a catalyst for converting sorbitol to light alkanes, comprising the following steps:

[0040] (1) Mix 5.57g of active nickel Ni(NO3)2·6H2O and 0.0443g of boron oxide B2O3 with 10mL of ammonia water, stir vigorously, add 5g of SiO2 sol with a mass percentage of 40%, and stir thoroughly.

[0041] (2) The light blue suspension obtained in step (1) was heated to 80°C and subjected to a water bath to evaporate ammonia. The suspension was heated to pH 6-8, filtered by vacuum pump, and the upper green solid was washed three times with deionized water. It was dried at 80°C overnight and calcined at 550°C in air for 3 h to obtain a black catalyst precursor.

[0042] (3) The black catalyst precursor obtained in step (2) was reduced at 600 °C for 1 h in a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes; the reducing atmosphere was a mixture of 5% H2 and 95% Ar; in the catalyst obtained after the reaction for converting sorbitol into light alkanes, the loading of active metal nickel was approximately 35 wt%, the doping amount of boron was 0.38 wt%, and the mass percentage of silicon was approximately 20 wt%. The boron oxide doping amount was 3 wt%.

[0043] Example 3

[0044] A method for preparing a catalyst for converting sorbitol to light alkanes, comprising the following steps:

[0045] (1) Mix 5.57g of active nickel Ni(NO3)2·6H2O and 0.108g of boron oxide B2O3 with 10mL of ammonia water, stir vigorously, add 5g of SiO2 sol with a mass percentage of 40%, and stir thoroughly.

[0046] (2) The light blue suspension obtained in step (1) was heated to 80°C and subjected to a water bath to evaporate ammonia. The suspension was heated to pH 6-8, filtered by vacuum pump, and the upper green solid was washed 4 times with deionized water. It was dried at 80°C overnight and calcined at 580°C in air for 3 h to obtain a black catalyst precursor.

[0047] (3) The black catalyst precursor obtained in step (2) was reduced at 600 °C for 1 h in a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes; the reducing atmosphere was a mixture of 5% H2 and 95% Ar; in the catalyst obtained after the reaction for converting sorbitol into light alkanes, the loading of active metal nickel was approximately 35 wt%, the doping amount of boron was 0.98 wt%, and the mass percentage of silicon was approximately 20 wt%. The boron oxide doping amount was 7 wt%.

[0048] Comparative Example 1

[0049] A method for preparing a catalyst for converting sorbitol to light alkanes, comprising the following steps:

[0050] (1) Mix 5.57g of active metal nickel Ni(NO3)2·6H2O and 0.075g of boron oxide B2O3 with 10 mL of ammonia water and stir vigorously to obtain a light blue suspension.

[0051] (2) The light blue suspension obtained in step (1) was heated to 80°C and subjected to a water bath to evaporate ammonia. The suspension was heated to pH 6-8, filtered by vacuum pump, and the upper green solid was washed 4 times with deionized water. It was dried at 80°C overnight and calcined at 600°C in air for 3 h to obtain a black catalyst precursor.

[0052] (3) The black catalyst precursor obtained in step (2) was reduced at 600 °C for 1 h in a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes; the reducing atmosphere was a mixture of 5% H2 and 95% Ar; in the catalyst obtained after the reaction for converting sorbitol into light alkanes, the loading of active metal nickel was approximately 35 wt%, the boron doping amount was 1.9 wt%, and the silicon mass percentage in the entire catalyst was 0 wt%. The boron oxide doping amount was 5 wt%.

[0053] Based on Example 1, in step (1), 5.57g of Ni(NO3)2·6H2O was added. The amount of boron oxide B2O3 added was adjusted to 0g, 0.014g (1wt% boron oxide doping), 0.029g (2wt% boron oxide doping), 0.044g (3wt% boron oxide doping), 0.1078g (7wt% boron oxide doping), and 0.1417g (9wt% boron oxide doping), respectively. The remaining operations were the same as in Example 1, and NiSi-PS-1, NiSi-PS-2, NiSi-PS-3, NiSi-PS-4, NiSi-PS-6, and NiSi-PS-7 catalysts were obtained respectively.

[0054] The catalyst prepared in Example 1 (0.075 g boron oxide B2O3 (5 wt% boron oxide doping)), the catalyst prepared in Comparative Example 1, and the above-mentioned NiSi-PS-1, NiSi-PS-2, NiSi-PS-3, NiSi-PS-4, NiSi-PS-6, and NiSi-PS-7 catalysts were applied to the reaction of sorbitol to light alkanes. Examples of their applications are as follows:

[0055] Application Example 1

[0056] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0057] (i) Place 1 g of sorbitol, 0.1 g of NiSi-PS-1 catalyst and 8 mL of tetradecane in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0058] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 280 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0059] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0060] Application Example 2

[0061] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0062] (i) Place 0.5 g of sorbitol, 0.15 g of the catalyst prepared in Example 1 and 8 mL of tetradecane solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0063] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 290 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0064] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0065] Application Example 3

[0066] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0067] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst prepared in Example 1 and 8 mL of tetradecane solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0068] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0069] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0070] Application Example 4

[0071] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0072] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-1 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0073] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300°C for 3 hours; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0074] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0075] Application Example 5

[0076] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0077] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-2 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0078] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0079] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0080] Application Example 6

[0081] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0082] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-3 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0083] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0084] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0085] Application Example 7

[0086] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0087] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-4 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0088] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300°C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0089] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0090] Application Example 8

[0091] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0092] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst prepared in Example 1 and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0093] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300°C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0094] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0095] Application Example 9

[0096] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0097] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst prepared in Example 1, and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0098] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 280 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0099] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0100] Application Example 10

[0101] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0102] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst prepared in Example 1, and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0103] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 290 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0104] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0105] Application Example 11

[0106] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0107] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst prepared in Example 1, and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0108] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 310 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0109] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0110] Application Example 12

[0111] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0112] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-6 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0113] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0114] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0115] Application Example 13

[0116] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0117] (i) Place 0.5 g of sorbitol, 0.2 g of NiSi-PS-7 catalyst and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0118] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300 °C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0119] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0120] Application Example 14

[0121] A catalyst for the conversion of sorbitol to light alkanes is described below. The operational steps for this application are as follows:

[0122] (i) Place 0.5 g of sorbitol, 0.2 g of the catalyst obtained in Comparative Example 1, and 10 mL of decahydronaphthalene solution in a 316L stainless steel high-pressure reactor and purge with H2 3-4 times;

[0123] (ii) Introduce H2 at a pressure of 5 MPa and maintain the reaction at 300°C for 3 h; stir continuously at a speed of 400 rpm throughout the entire reaction process;

[0124] (iii) After the reaction is complete, the 316L stainless steel high-pressure reactor is placed in ice water for rapid cooling. The gas after the reaction is collected using a 5L gas bag. The liquid obtained after the reaction is filtered to remove the catalyst. The obtained liquid is the product of sorbitol converted into light alkanes. The product is qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography with flame ionization detector (FID) and thermal conductivity detector (TCD), and high performance liquid chromatography (HPLC). The detailed results are shown in Table 1.

[0125] Table 1. Summary of Application Examples

[0126]

[0127] According to Table 1, comparing Application Examples 1 and 4, it is evident in Application Examples 2-4 and 5-14 that the introduction of boron oxide significantly promotes the yield of light alkanes obtained from the hydrogenation of sorbitol, regardless of whether the solvent is organic tetradecane or decahydronaphthalene. When the boron oxide doping concentration in the catalyst is 5 wt%, under optimized reaction conditions (300 °C, 5 MPa), a high yield of 88.9% of light alkanes can be achieved in just 3 hours. The tetradecane and decahydronaphthalene reaction media system selected in this invention, especially when decahydronaphthalene is used as the solvent, exhibits significant advantages in catalyst activity and thermal stability compared to common aqueous and two-phase systems.

[0128] The crystal structures of the catalyst prepared in Example 1 for converting sorbitol to light alkanes and the NiSi-PS-1 catalyst (before and after doping) were characterized using X-ray diffraction (XRD). The results are as follows: Figure 1 As shown, the broad XRD peak near 22° is attributed to the characteristic peaks of amorphous SiO2. And from... Figure 1 It is evident from this that the introduction of boron oxides makes the Ni-attributable... 0 The characteristic peaks are flatter, indicating that the introduction of boron resulted in more dispersed, finer Ni. 0 Species particles.

[0129] The microstructure of the catalyst prepared in Example 1 for converting sorbitol to light alkanes and the NiSi-PS-1 catalyst (before and after doping) were characterized using scanning electron microscopy (SEM). The results are as follows: Figure 2 and Figure 3 As shown. From Figure 2 , Figure 3 As can be seen, with the introduction of boron oxide, the catalyst changed from the original layered stacked nanosheet configuration to a structure with uniform nanoflower-like structure. This greatly increased the contact area between sorbitol and the catalyst, and improved the hydrogenation active sites. This further proves that the introduction of boron oxide has a significant promoting effect on the hydrogenation and deoxygenation of sorbitol to produce light alkanes.

[0130] The qualitative analysis of the gaseous products corresponds to example 8, and the results are as follows: Figure 4 .from Figure 4 As can be seen, the hydrogenation and deoxygenation of sorbitol yields the main light alkane products n-butane (A), n-pentane (B), and n-hexane (C), as well as isomerized methylcyclopentane (D) and cyclohexane (E) obtained by C / C bond rearrangement, and small amounts of monooxygen products (F) such as tetrahydrofuran, dimethyltetrahydrofuran, dipentamethyltetrahydrofuran, and tetrahydropyran. This indicates that the catalyst prepared in this invention exhibits significant advantages in selectively breaking CO bonds while retaining C / C bonds, ultimately yielding high-value light alkane products.

[0131] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A catalyst for converting sorbitol into light alkanes, characterized in that: Using non-precious metal nickel as the active component and SiO2 as the support, boron oxide was doped into the nickel-based catalyst obtained by the two. By controlling the amount of boron oxide added, a catalyst with a uniform nanoflower structure was obtained. The method for preparing the catalyst for converting sorbitol into light alkanes includes the following steps: (1) Mix active metal nickel and boron oxide with ammonia water, stir thoroughly, and add SiO2 sol; (2) The pH value was 6-8 after water bath heating, and the mixture was filtered. The upper solid was washed, dried overnight, and calcined in air to obtain a black catalyst precursor. (3) The black catalyst precursor obtained in step (2) is reduced under a reducing atmosphere to obtain a catalyst for converting sorbitol into light alkanes.

2. The catalyst for converting sorbitol to light alkanes according to claim 1, characterized in that: The amount of ammonia added in step (1) is 10 mL; the amount of SiO2 sol added is 5 g.

3. The catalyst for converting sorbitol to light alkanes according to claim 1, characterized in that: The active nickel component selected in step (1) is nickel salt Ni(NO3)2·6H2O, the boron oxide is B2O3, and the amount of nickel salt Ni(NO3)2·6H2O and the amount of B2O3 added is 400:1 to 40:1 by mass.

4. The catalyst for converting sorbitol to light alkanes according to claim 1, characterized in that: The ammonia water mentioned in step (1) is ammonia water with an ammonia (NH3) content of 25-28%; the SiO2 sol is SiO2 sol with a SiO2 content of 40%.

5. The catalyst for converting sorbitol to light alkanes according to claim 1, characterized in that: The water bath heating temperature in step (2) is 80℃; the calcination is 550-600℃ for 3 hours.

6. The catalyst for converting sorbitol to light alkanes according to claim 1, characterized in that: The reducing atmosphere described in step (3) is 5% hydrogen and 95% argon by volume, the reduction temperature is 600 °C, and the reduction time is 1 h.

7. The application of the catalyst for converting sorbitol to light alkanes as described in any one of claims 1-6 in the catalytic conversion of sorbitol to light alkanes.

8. The application as described in claim 7, characterized in that, The operation includes the following steps: (i) Sorbitol, the catalyst for converting sorbitol to light alkanes and the solvent are placed in a high-pressure reactor and purged with H2; the mass ratio of the catalyst for converting sorbitol to light alkanes to sorbitol is 1:2 to 1:

20. (ii) Introduce H2 and maintain the reaction at 250-310 °C for 0.5-10 h; (iii) After the reaction is complete, the high-pressure reactor is cooled rapidly, and the liquid after the reaction is collected, which is the product of sorbitol being converted into light alkanes.

9. The application as described in claim 8, characterized in that: The amount of sorbitol added in step (i) is 1-50% of the solvent mass, and the solvent is tetradecane or decahydronaphthalene; the pressure of H2 introduced in step (ii) is 3-8 MPa.

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