Porous organic polymer supported heteropolyacid heterogeneous catalyst, preparation method and application thereof

Abstract

The present application relates to the technical field of oil processing, in particular to a porous organic polymer supported heteropoly acid heterogeneous catalyst, a preparation method and application. The catalyst is prepared by impregnating method, in which the heteropoly acid is loaded in the porous organic polymer; and the heteropoly acid accounts for 10-50% of the total mass of the catalyst. The porous organic polymer is a nitrogen-rich porous organic polymer containing multiple secondary amine groups or imino groups, and the heteropoly acid is phosphomolybdic acid or silicotungstic acid. The catalyst has high heteropoly acid loading capacity; meanwhile, the N sites in the nitrogen-rich porous organic material carrier can reduce the agglomeration and dissolution of the heteropoly acid; on the basis of the heteropoly acid, the carrier is added, which is beneficial to the recycling of the catalyst; the catalyst provided by the present application has mild oxidation desulfurization reaction conditions, and can complete deep desulfurization of fuel oil in a short time at 40 DEG C, thereby reducing the desulfurization cost.

Description

Technical Field

[0001] The present invention relates to the technical field of oil processing, and in particular to a porous organic polymer-supported heteropolyacid heterogeneous catalyst, a preparation method and application thereof. Background Art

[0002] With the continuous development of the economy, people's demand for fuel is increasing, especially for fuel oil. However, the sulfides in fuel oil are complex in form and high in content. When burned in automobiles and industrial production, the sulfides in fuel oil will release toxic SO x , destroying the ecosystem and aggravating environmental pollution.

[0003] At present, oxidative desulfurization (ODS) is a major means of fuel desulfurization. It mainly uses oxygen or hydrogen peroxide as an oxidant to oxidize benzothiophene sulfide in fuel oil into sulfoxide and sulfone compounds with poor solubility in the oil phase. The sulfoxide and sulfone compounds can be subsequently separated from the fuel by extraction or precipitation to achieve the desulfurization effect.

[0004] Catalysts are required to improve the efficiency of oxidative desulfurization (ODS). Keggin-type heteropolyacids (POMs) exhibit some ODS catalytic activity. However, their low surface area and limited number of active sites limit their catalytic performance. Furthermore, the high solubility of POMs makes the catalyst difficult to separate and recover after desulfurization.

[0005] In recent years, loading POMs onto various supports has proven to be a highly effective strategy, resolving the recycling issues associated with homogeneous catalysis and significantly enhancing catalytic activity. However, using conventional supports such as activated carbon, silica, and molecular sieves, due to the lack of strong interactions with heteropolyacids, results in low POM loadings, leading to poor catalytic performance due to a low number of active components. Furthermore, due to the weak interaction between the support and the POMs, the POMs are easily dissolved during the desulfurization process, limiting the material's reusability. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and to provide a porous organic polymer-supported heteropolyacid heterogeneous catalyst, a preparation method and an application thereof, which has mild catalytic conditions, high desulfurization efficiency and is easy to separate and recover.

[0007] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0008] The present invention provides a porous organic polymer-supported heteropolyacid heterogeneous catalyst, which is prepared by loading a heteropolyacid solution into the pores of the porous organic polymer through an impregnation method. The heteropolyacid in the heterogeneous catalyst accounts for 10-50% of the total mass, and the porous organic polymer is a nitrogen-rich porous organic polymer. The nitrogen-containing groups of the nitrogen-rich porous organic polymer are conducive to the adsorption of anions under acidic conditions, and the heteropolyacid and the nitrogen-containing groups are tightly connected through electrostatic interaction, so as to increase the loading amount of the heteropolyacid and reduce the agglomeration and dissolution of the heteropolyacid.

[0009] Furthermore, the heteropoly acid is selected from Keggin-type phosphomolybdic acid or silicotungstic acid; and the porous organic polymer contains multiple secondary amino groups or imino groups with a pore size greater than 1 nm.

[0010] Furthermore, the porous organic polymer is selected from any one of PAF-54, TpPa-1, TpBpy and TpTt.

[0011] The present invention provides a method for preparing a porous organic polymer-supported heteropolyacid heterogeneous catalyst, comprising the following steps:

[0012] S1. Weighing a heteropoly acid and dissolving it in water to prepare a heteropoly acid aqueous solution; preparing a porous organic polymer;

[0013] S2, adding the porous organic polymer as a carrier to the heteropoly acid aqueous solution, stirring at room temperature for 24-48 hours to obtain a mixed solution;

[0014] S3, centrifuging the mixed solution to separate the precipitate, washing it with deionized water, and vacuum drying it at room temperature for 12-24 hours;

[0015] S4. Grind the dried solid to obtain a porous organic polymer-supported heteropolyacid heterogeneous catalyst.

[0016] Furthermore, when the porous organic polymer is PAF-54, the preparation method thereof is:

[0017] Weigh melamine and dissolve it in a dimethyl sulfoxide solution, and add triethylamine to prepare a mixed solution A; weigh cyanuric chloride and dissolve it in a dimethyl sulfoxide solution to prepare a mixed solution B; wherein the molar ratio of melamine to cyanuric chloride is 1:1; stir the mixed solution A at room temperature and a nitrogen atmosphere, and slowly add solution B thereto; after the addition is completed, increase the stirring rate and gradually raise the temperature to 150°C to react for 12-36 hours to obtain a milky white suspension; after the suspension is cooled to room temperature, filter it to obtain a white precipitate; wash the precipitate with dimethyl sulfoxide, deionized water and methanol, and vacuum dry it at room temperature for 12-24 hours; grind the precipitate to obtain a white powder to prepare PAF-54.

[0018] Furthermore, when the porous organic polymer is TpPa-1, its preparation method is:

[0019] Trialdehyde phloroglucinol and p-phenylenediamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried in vacuo at room temperature to obtain a brick-red solid. The brick-red solid is ground to obtain a brick-red powder to obtain TpPa-1.

[0020] Furthermore, when the porous organic polymer is TpBpy, its preparation method is:

[0021] Trialdehyde phloroglucinol and 2,2-bipyridine-5,5-diamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried in vacuo at room temperature to obtain a reddish-brown solid. The reddish-brown solid is ground to obtain a reddish-brown powder to prepare TpBpy.

[0022] Furthermore, when the porous organic polymer is TpTt, its preparation method is:

[0023] Trialdehyde phloroglucinol and melamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried under vacuum at room temperature to obtain a khaki solid. The khaki solid is ground to obtain a khaki powder to prepare TpTt.

[0024] The present invention provides an application of a porous organic polymer-supported heteropolyacid heterogeneous catalyst in the oxidative desulfurization of fuel oil.

[0025] Furthermore, the reaction conditions for fuel oxidative desulfurization are: reaction temperature 40-50°C, oxygen-sulfur ratio of oxidant H2O2 to sulfur content in fuel 4-6, reaction time 45-60min, and catalyst dosage 5-8g / L.

[0026] The present invention can achieve the following technical effects:

[0027] 1. The catalyst provided by the present invention uses nitrogen-rich porous organic matter as a carrier, and utilizes its high specific surface area and porosity to effectively increase the loading amount of the Keggin-type heteropoly acid catalyst, thereby promoting the mass transfer process of desulfurization catalysis;

[0028] 2. The large number of N sites in the nitrogen-rich porous organic carrier can strongly interact with the heteropoly acid, further increasing the loading capacity of the heteropoly acid. The N sites also play an anchoring role for the heteropoly acid, reducing the agglomeration and dissolution of the heteropoly acid, and further improving the effective utilization of the heteropoly acid.

[0029] 3. Adding a carrier to the heteropoly acid facilitates the recovery and reuse of the catalyst;

[0030] 4. The reaction conditions of catalytic oxidation desulfurization are mild, and it can complete the deep desulfurization of fuel in a short time at 40°C, reducing the desulfurization cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of Fourier transform infrared spectra of melamine, cyanuric chloride and PAF-54 prepared according to Example 1 of the present invention.

[0032] Figure 2 It is H3PMo provided by Example 1 of the present invention 12 O 40 And the prepared PAF-54, H3PMo 12 O 40 Schematic diagram of the Fourier infrared spectrum of @PAF-54.

[0033] Figure 3 H3PMo prepared according to Example 1 of the present invention 12 O 40 Schematic diagram of the water and oil contact angles of @PAF-54.

[0034] Figure 4 This is the N1s spectrum of PAF-54 prepared according to Example 1 of the present invention.

[0035] Figure 5 H3PMo prepared according to Example 1 of the present invention 12 O 40 @PAF-54's N1s spectrum.

[0036] Figure 6 It is H3PMo provided by Example 1 of the present invention 12 O 40 Mo3d spectrum diagram.

[0037] Figure 7 H3PMo prepared according to Example 1 of the present invention 12 O 40 Mo3d spectrum of @PAF-54.

[0038] Figure 8 Schematic diagram of catalytic desulfurization efficiency at different phosphomolybdic acid feed ratios in Application Example 2 of the present invention.

[0039] Figure 9 Schematic diagram of catalytic desulfurization efficiency at different temperatures in Application Example 2 of the present invention.

[0040] Figure 10 It is a schematic diagram of catalytic desulfurization efficiency under different oxygen-sulfur ratios in Application Example 2 of the present invention.

[0041] Figure 11 This is a schematic diagram of the optimal catalytic desulfurization rate curve of the catalyst prepared in Example 1 of Application Example 2 of the present invention.

[0042] Figure 12 This is a schematic diagram of catalytic desulfurization efficiency with different catalyst dosages in Application Example 4 of the present invention.

[0043] Figure 13 Schematic diagram of catalytic efficiency at different initial sulfur concentrations in Application Example 5 of the present invention.

[0044] Figure 14 Schematic diagram of the catalytic efficiency of different sulfur-containing compounds in Application Example 6 of the present invention.

[0045] Figure 15 It is a schematic diagram of the catalytic efficiency of the catalyst prepared according to Example 1 of the present invention at different cycle times.

[0046] Figure 16 3 is a schematic diagram showing the comparison of Fourier transform infrared spectra of the catalyst prepared according to Example 1 of the present invention after catalytic desulfurization. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0049] The present invention provides a porous organic polymer-supported heteropolyacid heterogeneous catalyst. The catalyst uses a porous organic polymer as a support and a heteropolyacid as an active component, which is loaded onto the porous organic polymer via an impregnation method. The heteropolyacid accounts for 10-50% of the total catalyst mass. The porous organic polymer is a nitrogen-rich porous organic polymer, as its high specific surface area and porosity facilitate increasing the heteropolyacid loading and promoting mass transfer during catalytic desulfurization.

[0050] Nitrogen-rich porous organic polymers contain a large amount of N, especially -NH- groups. Under acidic conditions, they are very conducive to the adsorption of anions. And due to the controllable pore size of porous organic polymers, it is easy to enter the pores. In addition, heteropoly acids can be firmly anchored on the N site through electrostatic interactions with the support. This strategy can greatly increase the loading capacity of heteropoly acids and prevent the loss of heteropoly acids due to dissolution. Using it as a catalyst support for oxidative desulfurization overcomes the problems of heteropoly acid homogeneous catalysts with few active sites due to low specific surface area and difficult catalyst separation and recovery due to high solubility. The presence of porous organic polymer supports is conducive to the recovery and reuse of catalysts.

[0051] Nitrogen-rich porous organic polymers contain a large number of N sites, which can interact strongly with heteropoly acids, further increasing the loading capacity of heteropoly acids; and the N sites play an anchoring role for heteropoly acids, reducing the agglomeration and dissolution of heteropoly acids, further improving the effective utilization of heteropoly acids.

[0052] In some specific embodiments, the porous organic polymer supported heteropoly acid heterogeneous catalyst provided by the embodiment of the present invention is selected from phosphomolybdic acid (H3PMo 12 O 40 ) or silicotungstic acid (H4SiW 12 O 40 ), the porous organic polymer contains multiple secondary amino groups or imino groups, and the pore size is greater than 1 nm, and one of PAF-54, TpPa-1, TpBpy and TpTt is selected.

[0053] The present invention also provides a method for preparing the above-mentioned porous organic polymer-supported heteropolyacid heterogeneous catalyst, comprising the following steps:

[0054] S1. Weighing a heteropoly acid and dissolving it in water to prepare a heteropoly acid aqueous solution; preparing a porous organic polymer support;

[0055] S2, adding the porous organic polymer support to the heteropoly acid aqueous solution, stirring at room temperature for 24-48 hours to obtain a mixed solution;

[0056] S3, centrifuging the mixed solution, washing with deionized water, and vacuum drying at room temperature for 12-24 hours;

[0057] S4. Grind the dried solid to obtain a porous organic polymer-supported heteropolyacid heterogeneous catalyst.

[0058] The porous organic polymer-supported heteropolyacid heterogeneous catalyst provided in the embodiment of the present invention can be used for fuel desulfurization. The reaction conditions for fuel desulfurization are: reaction temperature 40-50°C, oxygen-sulfur ratio of oxidant H2O2 to sulfur content in fuel of 4-6, reaction time 45-60min, and catalyst dosage 5-8g / L.

[0059] The following describes the details in conjunction with specific embodiments.

[0060] Example 1

[0061] Preparation of H3PMo 12 O 40 @PAF-54 heterogeneous catalyst A for oxidative desulfurization.

[0062] 567.5 mg of melamine was dissolved in 45 mL of dimethyl sulfoxide (DMSO) in a 100 mL beaker, and 0.6 mL of triethylamine was added to obtain a clear solution 1. 829.8 mg of cyanuric chloride was dissolved in 45 mL of DMSO in a 100 mL beaker to obtain a clear solution 2, where the molar ratio of melamine to cyanuric chloride was 1:1. Under a nitrogen atmosphere, solution 1 was transferred to a three-necked flask. Using a constant pressure dropping funnel, solution 2 was slowly added to solution 1 while stirring at 300 rpm at room temperature. A white precipitate gradually formed. The temperature was heated to 150°C over 60 minutes, the rotation speed was adjusted to 500 rpm, and then maintained at 150°C for 24 hours to obtain a milky white suspension. After cooling to room temperature, the resulting protein-colored precipitate was filtered and thoroughly washed with excess DMSO, deionized water, and methanol, and then dried under vacuum at room temperature for 24 hours. Finally, grind for 30 minutes to grind the white block solid into white powder to obtain the above-mentioned porous organic polymer carrier PAF-54 for use.

[0063] Weigh 100 mg of phosphomolybdic acid and dissolve it in 10 mL of aqueous solution to obtain a yellow phosphomolybdic acid aqueous solution. Then, add 100 mg of PAF-54 white powder to the above solution and stir at room temperature for 48 h. The solution becomes colorless and the white powder becomes blue-green. Centrifuge and wash three times with deionized water. Dry under vacuum at room temperature for 24 h to obtain a blue-green solid. Grind it for 30 min to grind it into a blue-green powder to obtain the above-mentioned H3PMo 12 O 40 @PAF-54 heterogeneous catalyst A for oxidative desulfurization.

[0064] Figure 1 The Fourier transform infrared spectra of melamine, cyanuric chloride and PAF-54 prepared in this embodiment are shown. Figure 1 The characteristic peak of triazine ring can be observed: 1548cm -1 , 1474cm -1, 1354cm -1 . At 813cm -1 A sharp peak appears at 848 cm, which is attributed to the bending vibration of the triazine ring. In addition, there is no C-Cl (848 cm) belonging to cyanuric chloride on PAF-54. -1 ) peak, indicating that cyanuric chloride and melamine have completely reacted to form PAF-54.

[0065] Figure 2 The H3PMo provided in Example 1 of the present invention is shown. 12 O 40 And the prepared PAF-54, H3PMo 12 O 40 @PAF-54 Fourier infrared spectrum. Figure 2 It can be observed that Keggin-type H3PMo 12 O 40 Characteristic peak: P=O a (a: tetrahedral O atom) is 1064 cm -1 , Mo-O b -Mo (b: edge-shared O atoms) is 874 cm -1 ;Mo-O c -Mo (c: corner-sharing O atoms) is 805 cm -1 , Mo=O d (d: terminal O atom) is 955 cm -1 , these four characteristic peaks can all be found in H3PMo 12 O 40 Observed on PAF-54, indicating successful loading of phosphomolybdic acid.

[0066] Figure 3 The H3PMo prepared in this example is shown 12 O 40 @PAF-54 catalyst water contact angle and oil contact angle. Figure 3 As shown, the contact angle between water and the catalyst is 57.2°, indicating that the catalyst is hydrophilic. When the water is replaced with oil, the oil droplets quickly penetrate the catalyst, indicating that the catalyst is superoleophilic. This demonstrates that the catalyst is amphiphilic, effectively contacting both H₂O₂ in the extractant phase and sulfur-containing compounds in the oil phase, thereby enhancing catalytic activity.

[0067] Figure 4 The N1s spectrum of PAF-54 prepared in this example is shown. Figure 5 The H3PMo prepared in this example is shown 12 O 40 @PAF-54's N1s spectrum, Figure 6 The H3PMo provided in this embodiment is shown 12 O40 Mo3d spectrum, Figure 7 The H3PMo provided in this embodiment is shown 12 O 40 @Mo3d spectrum of PAF-54.

[0068] like Figure 4 As shown, the N1s spectrum shows peaks at 398.53 eV and 399.81 eV, which are attributed to C=NC and NH; Figure 7 As shown, the peaks at 233.22 eV and 236.32 eV are attributed to Mo 6+ The binding energies of 231.15 eV and 234.93 eV correspond to Mo3d5 / 2 and Mo3d3 / 2, respectively. 5+ The double peak indicates that the Mo in PMo 6+ Partially reduced to Mo 5+ In the Keggin structure, Mo 5+ Replaced Mo 6+ , leading to the formation of heteropoly blue.

[0069] like Figure 6 and Figure 7 As shown, pure H3PMo 12 O 40 With H3PMo 12 O 40 Compared with @PAF-54, the binding energy of Mo3d is reduced; however, Figure 4 and Figure 5 As shown in the figure, the binding energy of N1s of PAF-54 increases compared with that of PMo@PAF-54. This indicates that electrons are transferred from the N site on PAF-54 to the Mo site on PMo, resulting in the Mo 5+ The formation of Mo 5+ It plays the role of an excellent active substance in the subsequent oxidative desulfurization process.

[0070] Example 2

[0071] Preparation of H4SiW 12 O 40 @PAF-54 heterogeneous catalyst B for oxidative desulfurization.

[0072] Take 567.5 mg of melamine and dissolve it in 45 mL of dimethyl sulfoxide solution in a 100 mL beaker, add 0.6 mL of triethylamine to obtain a clear solution 1. Take 829.8 mg of cyanuric chloride and dissolve it in 45 mL of dimethyl sulfoxide solution in a 100 mL beaker to obtain a clear solution 2, in which the molar ratio of melamine and cyanuric chloride is 1:1. Under a nitrogen atmosphere, transfer solution 1 to a three-necked flask. Using a constant pressure dropping funnel, slowly add solution 2 to solution 1 at room temperature with stirring at 300 rpm, and a white precipitate gradually appears in the solution. Heat the temperature to 150°C within 60 min, adjust the stirring speed to 500 rpm, then keep the reaction at 150°C for 24 h to obtain a milky white suspension. After cooling to room temperature, suction filter the white precipitate obtained, and wash it thoroughly with excess dimethyl sulfoxide, deionized water and methanol, and vacuum dry it at room temperature for 24 h. Finally, grind the white block solid for 30 min to grind it into a white powder to obtain the above-mentioned porous organic polymer carrier PAF-54 for standby.

[0073] Take 100 mg of silicotungstic acid and dissolve it in 10 mL of aqueous solution to obtain a colorless silicotungstic acid aqueous solution, then add 100 mg of PAF-54 white powder to the above-mentioned solution, stir at room temperature for 48 h, the solution is always colorless, centrifuge, wash with deionized water three times, vacuum dry at room temperature for 24 h to obtain a white solid, grind it for 30 min to grind it into a white powder to obtain the above-mentioned H4SiW 12 O 40 @PAF-54 oxidation desulfurization with heterogeneous catalyst B.

[0074] Example 3

[0075] Preparation of H3PMo 12 O 40 @PAF-54 oxidation desulfurization with heterogeneous catalyst C, D, E, F.

[0076] The preparation process is consistent with the preparation process of the heterogeneous catalyst A in Example 1, and the input amount of phosphotungstic acid is 25 mg, 33.3 mg, 50 mg and 200 mg respectively, and H3PMo 12 O 40 @PAF-54 heterogeneous catalyst C, D, E, F.

[0077] Example 4

[0078] Preparation of H3PMo 12 O 40 @TpPa-1 oxidation desulfurization with heterogeneous catalyst G.

[0079] Weigh 157.6 mg of trialdehyde phloroglucinol and 121.5 mg of p-phenylenediamine and dissolve them in 50 mL of dimethyl sulfoxide. Then transfer them to a 100 mL reactor and heat them at 120°C for 3 days. After cooling to room temperature, filter them and wash them with excess dimethyl sulfoxide and ethanol. Dry them in vacuo at room temperature to obtain a brick-red solid. Finally, grind it into a brick-red powder to obtain the above-mentioned porous organic polymer carrier TpPa-1 for later use.

[0080] 100 mg of phosphomolybdic acid was weighed and dissolved in 10 mL of aqueous solution to obtain a yellow phosphomolybdic acid aqueous solution. Then, 100 mg of TpPa-1 brick-red powder was added to the above solution, stirred at room temperature for 48 h, centrifuged, washed three times with deionized water, and vacuum-dried at room temperature for 24 h to obtain a red solid. The solid was ground for 30 min to obtain a red powder to obtain the above-mentioned H3PMo 12 O 40 @TpPa-1 Heterogeneous catalyst G for oxidative desulfurization.

[0081] Example 5

[0082] Preparation of H3PMo 12 O 40 @TpBpy Heterogeneous catalyst H for oxidative desulfurization.

[0083] Weigh 157.6 mg of trialdehyde phloroglucinol and 209.6 mg of 2,2-bipyridine-5,5-diamine and dissolve them in 50 mL of dimethyl sulfoxide. Then transfer them to a 100 mL reactor and heat them at 120°C for 3 days. After cooling to room temperature, filter and wash with excess dimethyl sulfoxide and ethanol. Dry under vacuum at room temperature to obtain a reddish-brown solid. Grind it into a reddish-brown powder to obtain the above-mentioned porous organic polymer carrier TpBpy for later use.

[0084] 100 mg of phosphomolybdic acid was weighed and dissolved in 10 mL of aqueous solution to obtain a yellow phosphomolybdic acid aqueous solution. 100 mg of TpPa-1 reddish brown powder was then added to the above solution, stirred at room temperature for 48 h, centrifuged, washed three times with deionized water, and vacuum dried at room temperature for 24 h to obtain a red solid. The solid was ground for 30 min to obtain a red powder to obtain the above-mentioned H3PMo 12 O 40 @TpPa-1 Heterogeneous catalyst H for oxidative desulfurization.

[0085] Example 6

[0086] Preparation of H3PMo 12 O 40 @TpTtHeterogeneous catalyst for oxidative desulfurization I.

[0087] Weigh 157.6 mg of trialdehyde phloroglucinol and 94.5 mg of melamine and dissolve them in 50 mL of dimethyl sulfoxide. Then transfer them to a 100 mL reactor and heat them at 120°C for 3 days. After cooling to room temperature, filter them and wash them with excess dimethyl sulfoxide and ethanol. Dry them in vacuo at room temperature to obtain a khaki solid. Grind it into a khaki powder to obtain the above-mentioned porous organic polymer carrier TpTt, which is set aside.

[0088] Weigh 100 mg of phosphomolybdic acid and dissolve it in 10 mL of aqueous solution to obtain a yellow phosphomolybdic acid aqueous solution. Then, add 100 mg of TpTt khaki powder to the above solution, stir at room temperature for 48 h, centrifuge, wash three times with deionized water, and vacuum dry at room temperature for 24 h to obtain a yellow solid. Grind it for 30 min to obtain a yellow powder to obtain the above-mentioned H3PMo 12 O 40 @TpTtHeterogeneous catalyst for oxidative desulfurization I.

[0089] Application Example 1

[0090] This application example verifies the catalytic degradation performance of the catalysts prepared in Examples 1-6. Catalysts A1 and A1 are used to conduct oxidation desulfurization experiments. The reaction formula is as follows:

[0091]

[0092] The specific steps are as follows:

[0093] In 100mL n-octane, add 460.6mg dibenzothiophene (DBT), be made into the simulation diesel oil of 800ppm of sulfur content, standby.Desulfurization experiment is carried out in 20mL glass sample bottle, add 1mL model oil (0.025mmolDBT), 1mL acetonitrile, 0.1mmol hydrogen peroxide and 5mg above-mentioned catalyst.Water bath is heated to 40 ℃, and rotating speed is adjusted to 540rpm, and reaction is 45min.After reaction finishes, centrifugal with separation catalyst, in reaction solution, add 1mL toluene / dichloromethane mixture (50%, v / v) and naphthalene (interior standard, 7.5mg) to form homogeneous solution, and by gas chromatographic analysis gained solution, calculate catalytic efficiency.

[0094] Where, catalytic efficiency = n DBTO2 / n0×100%;

[0095] The calculation results are shown in the following table:

[0096] Catalyst Catalytic efficiency Catalyst A 100％ Catalyst B 44.5％ Catalyst C 61.2％ Catalyst D 77.2％ Catalyst E 83.3％ Catalyst F 71.5％ Catalyst G 24.9％ Catalyst H 93.7％ Catalyst I 24.1％

[0097] Application Example 2

[0098] This application example verifies the effect of catalytic temperature on catalyst activity. The oxidation reaction temperature is adjusted. The experimental steps are similar to those in Application Example 1, as follows:

[0099] Desulfurization experiments were conducted in 20 mL glass vials. 1 mL of model oil (0.02 mmol DBT), 1 mL of acetonitrile, 0.1 mmol hydrogen peroxide, and 5 mg of catalyst were added. The reaction was heated in a water bath to 30, 35, 40, 45, and 50°C, with the rotational speed adjusted to 540 rpm, and the reaction was continued for 45 min. After the reaction, the catalyst was separated by centrifugation. 1 mL of a 50% v / v toluene / dichloromethane mixture and 7.5 mg of naphthalene (internal standard) were added to the reaction solution to form a homogeneous solution. The resulting solution was analyzed by gas chromatography, and the catalytic efficiency was calculated.

[0100] Figure 8 The catalytic desulfurization efficiency of different phosphomolybdic acid feed ratios is shown. Figure 8 It can be seen that the catalytic desulfurization efficiency shows a trend of first increasing and then decreasing with the increase of the phosphomolybdic acid feed ratio. When the ratio of phosphomolybdic acid to PAF-54 is 1:1, the desulfurization efficiency reaches the maximum value.

[0101] Figure 9 The catalytic desulfurization efficiency at different temperatures is shown. Figure 9 It can be seen that within the range of 35-50°C, as the temperature increases, the catalytic efficiency increases significantly, reaching a peak at 40°C with a catalytic efficiency of 100%. Taking energy consumption into consideration, 40°C is selected as the optimal catalytic temperature.

[0102] Application Example 3

[0103] This application example verifies the effect of the oxygen-sulfur ratio, that is, the amount of oxidant, on the catalyst activity. Different amounts of hydrogen peroxide are added. The experimental steps are similar to those in Application Example 1, as follows:

[0104] Desulfurization experiments were conducted in 20 mL glass vials. 1 mL of model oil (0.025 mmol DBT), 1 mL of acetonitrile, 0.05, 0.075, 0.1, 0.125, and 0.15 mmol hydrogen peroxide, and 5 mg of the above catalyst were added. The reaction was heated to 40°C in a water bath at 540 rpm for 45 min. After completion of the reaction, the catalyst was separated by centrifugation. 1 mL of a 50% v / v toluene / dichloromethane mixture and 7.5 mg of naphthalene (internal standard) were added to the reaction solution to form a homogeneous solution. The resulting solution was analyzed by gas chromatography, and the catalytic efficiency was calculated.

[0105] Figure 10 The catalytic desulfurization efficiency under different oxygen-sulfur ratios is shown. Figure 10As can be seen, as the oxidant dosage increases, the reaction proceeds in the forward direction, accelerating the catalytic rate. At an oxygen-sulfur ratio of 4, or 0.1 mmol of hydrogen peroxide, the catalytic efficiency reaches 100%. Further increases in the oxidant dosage maintain 100% conversion. Therefore, considering catalytic cost, an oxygen-sulfur ratio of 4 is selected as the optimal oxidant dosage.

[0106] Figure 11 The optimal catalytic desulfurization rate of the catalyst prepared in Example 1 is shown. Figure 11 It can be seen that as the reaction time increases, the conversion rate of the catalytic reaction gradually increases. When the reaction time is 45 minutes, the conversion rate reaches the maximum value. Thereafter, the conversion rate remains unchanged as the reaction time increases. Therefore, 45 minutes is selected as the optimal reaction time.

[0107] Application Example 4

[0108] This application example verifies the effect of catalyst dosage on catalyst activity. Different amounts of hydrogen peroxide are added. The experimental steps are similar to those in Application Example 1, as follows:

[0109] Desulfurization experiments were conducted in 20 mL glass vials. 1 mL of model oil (0.025 mmol DBT), 1 mL of acetonitrile, 0.05, 0.075, 0.1, 0.125, and 0.15 mmol hydrogen peroxide, and 5 mg of the above catalyst were added. The reaction was heated to 40°C in a water bath at 540 rpm for 45 min. After completion of the reaction, the catalyst was separated by centrifugation. 1 mL of a 50% v / v toluene / dichloromethane mixture and 7.5 mg of naphthalene (internal standard) were added to the reaction solution to form a homogeneous solution. The resulting solution was analyzed by gas chromatography, and the catalytic efficiency was calculated.

[0110] Figure 12 The catalytic desulfurization efficiency of different catalyst dosages is shown. Figure 12 It can be seen that when the catalyst dosage is increased from 2g / L to 5g / L, the catalytic efficiency is significantly improved, and 100% catalytic efficiency can be reached in 45 minutes; when the catalyst dosage is further increased to 8g / L, desulfurization can be completed within 30 minutes.

[0111] Application Example 5

[0112] This application example verifies the effect of different initial sulfur concentrations on catalytic efficiency. Catalysis is performed using simulated fuels containing sulfur at different concentrations. The experimental steps are similar to those in Application Example 1 and are as follows:

[0113] Desulfurization experiments were conducted in 20 mL glass vials. 1 mL of model oil (500, 800, and 1000 ppm DBT), 1 mL of acetonitrile, 0.1 mmol of hydrogen peroxide, and 5 mg of the above catalyst were added. The reaction was heated to 40°C in a water bath at 540 rpm for 45 minutes. After completion of the reaction, the catalyst was separated by centrifugation. 1 mL of a 50% v / v toluene / dichloromethane mixture and 7.5 mg of naphthalene (internal standard) were added to the reaction solution to form a homogeneous solution. The resulting solution was analyzed by gas chromatography, and the catalytic efficiency was calculated.

[0114] Figure 13 The catalytic desulfurization efficiency of different initial sulfur concentrations is shown. Figure 13 It can be seen that the catalytic rates when the initial sulfur contents are 500, 800, and 1000 ppm are similar, and 100% desulfurization catalysis can be completed within 45 minutes, demonstrating the excellent performance of the catalyst.

[0115] Application Example 6

[0116] This application example verifies the effect of different sulfur compounds on catalytic efficiency. Catalysis is performed using simulated fuel containing different sulfur compounds. The experimental steps are similar to those in Application Example 1 and are as follows:

[0117] Desulfurization experiments were conducted in 20 mL glass vials. 1 mL of model oil (0.025 mmol of BT, 4,6-DMDBT, DBT), 1 mL of acetonitrile, 0.1 mmol of hydrogen peroxide, and 5 mg of the above catalyst were added. The mixture was heated to 40°C in a water bath at 540 rpm and allowed to react for 45 minutes. After completion of the reaction, the catalyst was separated by centrifugation. 1 mL of a 50% v / v toluene / dichloromethane mixture and 7.5 mg of naphthalene (internal standard) were added to the reaction solution to form a homogeneous solution. The resulting solution was analyzed by gas chromatography, and the catalytic efficiency was calculated.

[0118] Figure 14 The catalytic efficiency of different sulfur compounds is shown. Figure 14 It can be seen that the catalyst has a rapid catalytic effect on DBT and 4,6-DMDBT, and can completely remove sulfur-containing compounds within 45 minutes; while for BT, only 70% conversion rate can be achieved in 45 minutes, which is related to the electron density of sulfur-containing compounds, BT (5.739) <DBT(5.758)<4,6-DMDBT(5.760)。

[0119] Figure 15 The catalytic efficiency of the catalyst prepared in Example 1 at different cycle times is shown. Figure 15 It can be seen that after 6 cycles of catalysis in Application Examples 1-6, the catalytic activity still did not decrease and was still maintained at 100%.

[0120] Figure 16 The Fourier transform infrared spectrum comparison of the catalyst prepared in Example 1 after catalytic desulfurization is shown. Figure 16 It can be seen that the two infrared spectra before and after catalysis are basically consistent, indicating that the catalyst has not changed during the catalytic process, proving that the catalyst prepared in the embodiment of the present invention has excellent stability.

[0121] The model oil was tested after each cycle using an inductively coupled plasma mass spectrometer (ICP-MS). The test results are shown in the following table:

[0122]

[0123] The concentration of dissolved Mo is very low and almost negligible, further demonstrating the excellent stability of the catalyst during the catalytic process, indicating the strong interaction between PAF and the host-guest phosphomolybdic acid.

[0124] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0125] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0126] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A porous organic polymer-supported heteropolyacid heterogeneous catalyst, characterized in that: The heterogeneous catalyst is prepared by loading a heteropoly acid into the pores of a porous organic polymer by an impregnation method. The heteropoly acid in the heterogeneous catalyst accounts for 10-50% of the total mass. The porous organic polymer is a nitrogen-rich porous organic polymer. The nitrogen-containing groups of the nitrogen-rich porous organic polymer are conducive to the adsorption of anions under acidic conditions. The heteropoly acid and the nitrogen-containing groups are tightly connected through electrostatic interactions, thereby increasing the loading amount of the heteropoly acid and reducing the agglomeration and dissolution of the heteropoly acid. The heteropoly acid is selected from Keggin-type phosphomolybdic acid or silicotungstic acid; the porous organic polymer contains multiple secondary amino groups or imino groups with a pore size greater than 1 nm; the porous organic polymer is selected from any one of PAF-54, TpPa-1, TpBpy and TpTt; The preparation method comprises: adding a porous organic polymer carrier to a heteropoly acid aqueous solution, stirring at room temperature for 24-48 hours to obtain a mixed solution; centrifuging the mixed solution, washing it with deionized water, and vacuum drying it at room temperature for 12-24 hours.

2. The method for preparing the porous organic polymer-supported heteropolyacid heterogeneous catalyst according to claim 1, characterized in that: The steps include: S1. Weighing a heteropoly acid and dissolving it in water to prepare a heteropoly acid aqueous solution; preparing a porous organic polymer; S2, adding the porous organic polymer as a carrier to the heteropoly acid aqueous solution, stirring at room temperature for 24-48 hours to obtain a mixed solution; S3, centrifuging the mixed solution to separate the precipitate, washing it with deionized water, and vacuum drying it at room temperature for 12-24 hours; S4. Grinding the dried solid to obtain the porous organic polymer-supported heteropolyacid heterogeneous catalyst.

3. The preparation method according to claim 2, characterized in that When the porous organic polymer is PAF-54, the preparation method thereof is as follows: Weigh melamine and dissolve it in a dimethyl sulfoxide solution, and add triethylamine to prepare a mixed solution A; weigh cyanuric chloride and dissolve it in a dimethyl sulfoxide solution to prepare a mixed solution B; wherein the molar ratio of melamine to cyanuric chloride is 1:1; stir the mixed solution A at room temperature and a nitrogen atmosphere, and slowly add solution B thereto; after the addition is completed, increase the stirring rate and gradually raise the temperature to 150°C, react for 12-36 hours to obtain a milky white suspension; after the suspension is cooled to room temperature, filter it to obtain a white precipitate; wash the precipitate with dimethyl sulfoxide, deionized water and methanol, and vacuum dry it at room temperature for 12-24 hours; grind the precipitate to obtain a white powder to prepare PAF-54.

4. The preparation method according to claim 2, characterized in that When the porous organic polymer is TpPa-1, the preparation method thereof is: Trialdehyde phloroglucinol and p-phenylenediamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried in vacuo at room temperature to obtain a brick-red solid. The brick-red solid is ground to obtain a brick-red powder to obtain TpPa-1.

5. The preparation method according to claim 2, characterized in that When the porous organic polymer is TpBpy, its preparation method is: Trialdehyde phloroglucinol and 2,2-bipyridine-5,5-diamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried in vacuo at room temperature to obtain a reddish-brown solid. The reddish-brown solid is ground to obtain a reddish-brown powder to prepare TpBpy.

6. The preparation method according to claim 2, characterized in that When the porous organic polymer is TpTt, the preparation method thereof is: Trialdehyde phloroglucinol and melamine are weighed and dissolved in dimethyl sulfoxide, and heated at 120-150° C. for 24-72 hours. After cooling to room temperature, the precipitate is filtered to obtain a precipitate, which is washed with dimethyl sulfoxide and ethanol and dried under vacuum at room temperature to obtain a khaki solid. The khaki solid is ground to obtain a khaki powder to prepare TpTt.

7. Use of the porous organic polymer-supported heteropolyacid heterogeneous catalyst according to claim 1 in the oxidative desulfurization of fuel oil.

8. The use according to claim 7, characterized in that The reaction conditions for the fuel oxidative desulfurization are: reaction temperature 40-50°C, oxygen-sulfur ratio of oxidant H2O2 to sulfur content in the fuel of 4-6, reaction time 45-60min, and catalyst dosage 5-8g / L.

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