200-380nm ultraviolet light catalytic oxidation diesel oil deep desulfurization method

The technical field of the deep desulfurization method of diesel oil by ultraviolet photocatalytic oxidation with wavelength of 200~380nm

[0001] The present invention relates to the field of homocatalysis. It is a method for deep desulfurization of diesel fuel by ultraviolet photocatalytic oxidation at a wavelength of 200 to 380 nm, and in particular to a method for preparing a heteropolyacid modified TiO2 photocatalyst and a method for preparing ultraviolet light diesel at a wavelength of 200 to 380 nm. Desulfurization method.

Background technique

[0002] In recent years, environmental problems such as atmospheric ozone layer destruction, air pollution, and energy shortages have become increasingly serious, and how to deal with environmental pollution problems has become an important research topic for scientists. With the rapid development of the country's economic strength and the rapid development of fossil fuels, the storage of fossil fuels is gradually depleted, and the continuous mining makes its natural storage capacity unsustainable. The post-processing method of burning fossil energy directly is a great challenge to the environment. The sulfur-containing components in vehicle diesel will increase the environmental emissions of SOx and damage the service life of the vehicle exhaust converter and the vehicle. The sulfur content in the exhaust exhaust gas is one of the main causes of acid rain, and it also causes damage to the environment. Pollution and damage to human health. However, in today's world's main crude oil energy composition, most crude oils of lower quality have high sulfur content. Therefore, exploring the desulfurization process of diesel is one of the important ways to solve the environmental pollution in our country. Controlling the sulfur content in fuel oil and reducing the sulfur content through catalytic conversion is one of the ways to alleviate environmental pressure and improve energy quality, which meets the requirements of green chemistry.

[0003] However, when the sulfur content of the diesel fuel is less than 500 ppm, it is difficult to completely remove the sulfur compounds in the diesel fuel. Moreover, it is difficult to completely oxidize the diesel fuel to deeply desulfurize the diesel in the prior art involving ultraviolet light with a wavelength of 200 to 380 nm. Therefore, the present invention relates to a method for deep desulfurization of diesel fuel by ultraviolet photocatalytic oxidation at a wavelength of 200 to 380 nm, focusing on a method for desulfurizing fuel oil with a sulfur content of less than 500 ppm, and thoroughly removing sulfide.

Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for deep desulfurization of diesel oil by ultraviolet photocatalysis and oxidation at a wavelength of 200~380nm, and further specifically a heteropolyacid modified TiO2 photocatalyst and a preparation method thereof, and including diesel depth Desulfurization method.

[0005] The present invention solves the above technical problems and relates to a deep desulfurization method. The technical solution is as follows: A method for deep desulfurization of diesel fuel with a wavelength of 200-380 nm through ultraviolet photocatalytic oxidation. The steps are as follows: Step 1. The titanium source and the heteropoly acid are in accordance with Dissolve in ethanol with a molar ratio of 5:1 to obtain a white turbid liquid. Adjust the pH to 3~6 with alkali, stir vigorously for 0.5-2 h until the mixture is stable, and then add hydrofluoric acid dropwise. Among them, hydrofluoric acid The molar ratio to the titanium source is 2~5:1, and the stirring is continued for 0.5-1 h and then placed at 160~200 ⁰After 20-30 h of hydrothermal reaction under c condition, after centrifugation, washing, drying, put it in a muffle furnace for 1^oC/min heating rate 350~450 ⁰c calcine for 0.5~3 h, then take out and grind to powder to obtain heteropolyacid modified TiO2 photocatalyst, where the titanium source is titanium isopropoxide (Ti[OCH (CH3) 2]4), titanate Butyl ester, any one of titanium tetrachloride, the heteropoly acid is (NH4) 3Co (OH) 6MO6, [(C18H37) 2N (CH3) 2] 3Co (OH) 6MO6O18, [PyPS] 3Co (OH) ) Any one of 6MO6O18; The alkali is any one of ammonia, sodium hydroxide, and sodium bicarbonate;

Step 2. The heteropolyacid-modified TiO2 photocatalyst prepared in Step 1 is mixed with DBT in diesel at a mass ratio of h5:1, and then placed in a photocatalytic reactor at 0-60 °C, protected from light, and circulating water. Stir the reaction for 0.2~1h to reach the extraction equilibrium, and then add oxygen from the photocatalytic reactor, and the molar ratio of oxygen in the oxygen source to sulfur in the diesel DBT is 3~5:1, and then The deep desulfurization can be completed by the catalytic oxidation desulfurization reaction house for 5 hours under the condition of ultraviolet light with a wavelength of 200~380 nm, wherein the sulfur content of the diesel DBT is W500 ppm, and the oxygen source is any one of H2O2O2 and tert-butyl hydrogen peroxide. Step 3. After the reaction is over, let it stand until it is stratified, and the upper layer of diesel is decanted out to obtain desulfurized diesel.

[0006] Preferably, the alkali in step 1 is ammonia.

[0007] Preferably, the titanium source in step 1 is titanium isopropoxide (Ti[OCH(CH3)2]4).

[0008] Preferably, the pH is adjusted to 5-6 in step 1.

[0009] A preferred feature is that the hydrothermal reaction temperature in step 1 is 200C.

[0010] Preferably, the oxygen source in step 2 is H2O2.

[0011] The present invention solves another technical problem and relates to a photocatalyst for deep desulfurization. The technical solution is as follows: The heteropolyacid-modified TiO2 photocatalyst prepared in step 1 of the above-mentioned diesel deep desulfurization method is suitable for a wavelength of 200 Deep desulfurization by catalytic oxidation under ~380 nm ultraviolet light.

[0012] It is well known that DBT has stable performance and is not easy to be oxidized. The innovation of the present invention is characterized in that the heteropolyacid modified TiO2 photocatalyst improves the energy level matching degree in the photocatalytic system, thereby catalytically oxidizing the sulfide (DBT) in the model diesel into sulfones and extracting and separating to achieve deep desulfurization; further According to the analysis, the catalyst prepared by the present invention uses the energy level adjustable performance of heteropoly acid to modify titanium dioxide, and adjusts the energy level of the catalyst combined with titanium dioxide by changing the type and amount of different heteropoly acid, and forms a stable and recyclable solid phase catalyst Further, as shown in Figure 1, the energy level of the heteropolyacid-modified catalyst prepared by the present invention changes under the condition of ultraviolet light with a wavelength of 200~380nm. According to the type and central atom of the heteropolyacid, the main catalyst titanium dioxide The conduction band will move down, the forbidden band width is reduced, the utilization rate of the catalyst to sunlight is improved, the catalyst is more sensitive to the sulfur compounds (DBT) in diesel, and the performance of photo-generated electrons and holes is improved. Faster electron transmission rate and longer electron transmission distance. Under the activation of oxidant, DBT can be more efficiently oxidized to generate sulfones. The sulfones can be separated by simple separation methods to obtain fuel with extremely low sulfur content. The energy level matching of the diesel photocatalytic oxidative desulfurization catalyst is not high enough, and the photocatalytic efficiency is low due to the unsatisfactory transmission rate and transmission distance of photogenerated electrons and holes.

[0013] The beneficial effects of the present invention are:

1) The process of the present invention is simple to operate, and the reaction conditions are mild, and the heteropolyacid modified TiO2 photocatalyst of the present invention can be recycled.

[0014] 2) The diesel deep desulfurization of the present invention is effective for ultraviolet light at a wavelength of 200 to 380 nm.

[0015] 3) The method of the present invention can achieve 90% to 100% desulfurization effect of ultraviolet light with a wavelength of 200-380nm, and has the photoselectivity of deep desulfurization, and is much higher than the prior art titanium dioxide photocatalytic desulfurization effect (W50%) Among them, the optimal (NH4) 3C0 (OH) 6M06/TiO2 (ie Co-Mo/TiO2) catalyst desulfurization rate can reach 100% to completely remove sulfur.

[0016] 4) The diesel deep desulfurization reaction time of the present invention is short, and the reaction can be completed within 1 to 5 hours.

[0017] 5) The present invention can not only selectively and deeply remove sulfur in diesel oil in the process of ultraviolet light with a wavelength of 200~380nm

In addition, the catalyst preparation process is simple and efficient, and the use of precious metals is avoided, which reduces the cost of desulfurization and has greater economic benefits, and the catalyst can be recycled and is green and pollution-free.

Description of the drawings

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention, and constitute a part of it, together with the specific embodiments of the present application, are used to explain the technical solution of the present invention, and do not constitute a limitation to the technical solution of the present invention.

[0019] Figure 1 is the catalytic performance mechanism of the desulfurization process of the present invention.

[0020] FIG. 2 is a SEM test diagram of the catalyst prepared in Example 1 of the present invention.

[0021] FIG. 3 is an XRD test chart of the catalyst prepared in Example 1 of the present invention.

[0022] FIG. 4 is a catalytic performance test chart of the recycling catalyst of Example 1 of the present invention (5 cycles).

[0023] FIG. 5 is a comparison diagram of the catalytic effects of (Co-Mo/TiO2, (NH4)3Co(0H)6MO6, TiO2) in Example 1 of the present invention.

[0024] FIG. 6 is a test diagram of the catalytic performance of the catalyst in Example 1 of the present invention under different light conditions (380~780 nm, 200~380 nm, protected from light).

[0025] FIG. 7 is a test diagram of the light absorption ability of different catalysts (Co-Mo/TiO2, (NH4)3Co(0H)6Mo6, TiO2) in Example 1 of the present invention.

[0026] FIG. 8 is a scanning electron micrograph of the catalyst Ni-Mo/TiO2 in Example 2 of the present invention.

[0027] FIG. 9 is a catalytic performance test chart of the recycling catalyst of Example 2 of the present invention (5 cycles).

[0028] FIG. 10 is a catalyst of Example 2 of the present invention 2-Co-Mo/TiO2, [(C18H37) 2N (CH3) 213Co (0H) 6M. 6.18 and TiO2 catalytic performance test chart.

[0029] FIG. 11 is an XPS test chart of the valence band spectrum of the catalyst 3-Co-Mo/TiO2 in Example 3 of the present invention.

[0030] FIG. 12 is a catalytic performance test diagram of the recycling of the catalyst in Example 3 of the present invention (4 cycles).

[0031] FIG. 13 is an infrared test chart of the catalyst prepared in Example 4 of the present invention.

[0032] FIG. 14 is a test diagram of the catalytic performance of the catalyst prepared in Example 4 of the present invention under different light conditions (380-780 nm, 200-380 nm, and light-shielding).

Detailed ways

[0033] The present invention will be described in more detail below with reference to the accompanying drawings, which show preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein and still achieve the beneficial effects of the present invention. Therefore, the following description should be understood to be widely known to those skilled in the art, and not as a limitation to the present invention. [0034] For the sake of clarity, not all features of actual embodiments are described. In the following description, well-known functions and structures are not described in detail because they may confuse the present invention due to unnecessary details. It should be considered that in the development of any actual embodiment, a large number of implementation details must be made to achieve the developer's specific goals.

[0035] The following describes the principles and features of the present invention, the examples cited are only used to explain the present invention, not to limit the scope of the present invention, and it should be noted that the DBT content of the model diesel tested in the following examples is W500 ppm .

Example 1

1) Preparation of (NH4) 3Co (oh) 6Mo6/TiO2 (ie Co-Mo/TiO2) catalyst: heteropoly acid (NH4) 3Co (oh) 6Mo6: titanium isopropoxide = 1:7 (mass ratio) mixed and dissolved Ethanol, adjust pH=5 with ammonia water, stir vigorously for 1 h after the mixture is stable, add hydrofluoric acid dropwise (the molar ratio of titanium source: hydrofluoric acid = 5:1) and continue to stir for 0.5 h before placing it at 200 ⁰Hydrothermal reaction under c condition 24

h. After the reaction, cool to room temperature, centrifuge, dry, wash, and place in a muffle furnace for 1^oThe heating rate of C/min is 450 ⁰c After calcination for 0.5 h, the Co-Mo/TiO2 catalyst is obtained by grinding to powder. As shown in the electron microscope test in Figure 2, the catalyst is round nanoparticles.

[0037] The XRD test of the catalyst in Figure 3 shows the organic combination of titanium dioxide and heteropolyacid in the catalyst, mainly showing the characteristic peaks of TiO2. In addition, the XPS test shows that it contains Ti, O, Co, Mo and C elements, which proves that Co-Mo/ The successful synthesis of TiO2 catalyst.

[0038] Desulfurization reaction: Add 20 mL of 500 ppm model oil and 0.1 g of catalyst to the photocatalytic reactor, stir for 0.5h under the conditions of dark, °C, and circulating water to reach the extraction equilibrium, and then pipette 0.176 mL of 30% H2O2 (O/S=5) was added to the mixed solution, the xenon lamp was turned on, and the photocatalytic oxidation reaction experiment was carried out under the conditions of 200-380 nm ultraviolet light (reaction time 3h).

[0039] Qualitative and quantitative analysis of the desulfurization reaction: using GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

[0040] The test results show that the desulfurization rate of the 30% catalyst can reach 100% after 3 h.

[0041] 2) Co-Mo/TiO2 catalyst cycle test: After the reaction, the reaction substrate in the photocatalytic reactor is centrifuged and washed with deionized water and ethanol, and the collected Co-Mo/TiO2 catalyst is dried in an oven That is, the catalyst is then recycled for desulfurization.

[0042] The same model diesel as in the above-mentioned embodiment was selected, and the separated Co-Mo/TiO2 catalyst was used repeatedly for 5 times for deep desulfurization according to the same test parameters and steps.

[0043] After the completion of desulfurization, qualitative and quantitative analysis of 5 deep desulfurization tests were performed: as shown in Figure 4, the first 3h desulfurization rate was 100%, the second 3h desulfurization rate was 100%, and the third 3h desulfurization rate was 98.2 %, the 4th 3h desulfurization rate was 97.5%, and the 5th 3h desulfurization rate was 95.3%, which proved that the heteropolyacid-modified TiO2 photocatalyst of the present invention can be recycled and the catalytic oxidation effect hardly changes. Among them, The difference in desulfurization effect lies in the unavoidable quality loss during the catalyst recovery process.

[0044] 3) Comparative test of heteropoly acid (NH4) 3Co (OH) 6Mo6, TiO2 catalyst: The same test method steps as the above embodiment, the difference is that the catalyst Co-Mo/TiO2 is replaced with heteropoly acid ( NH4) 3Co (OH) 6Mo6 catalyst, the qualitative and quantitative analysis of the test showed that the desulfurization rate was 85.2% in 3 hours.

[0045] The same test method steps as the above embodiment, the difference is that the catalyst Co-Mo/TiO2 is replaced with a TiO2 catalyst, and the qualitative and quantitative analysis of the test shows that the 3h desulfurization rate is 63.6%.

[0046] As shown in FIG. 5, the Co-Mo/TiO2 catalyst is compared with heteropolyacid (NH4) 3Co (OH) 6Mo6 and TiO2 catalysts. The Co-Mo/TiO2 catalyst can be Complete desulfurization. It shows that the catalyst of the present invention has a significantly improved catalytic effect. Compared with using two catalysts alone, the catalytic efficiency is greatly improved, which proves that the unique structure of the new synthetic catalyst is a new type of catalyst more suitable for oxidative desulfurization.

[0047] 4) 380~780 nm visible light comparison test: The same test method steps as the above embodiment, the difference is that the 200~380 nm ultraviolet light illumination condition is replaced with 380~780 nm visible light, the test is qualitative and quantitative analysis, the test shows 3h The desulfurization rate is only 78%.

[0048] The same test method steps as the above embodiment, the difference is that the 200-380 nm ultraviolet light conditions are replaced with no light conditions, the test qualitative and quantitative analysis, the test shows that the 3h desulfurization rate is 58%.

[0049] As shown in FIG. 6, the catalyst of the present invention can only desulfurize 100% under the conditions of 200-380 nm ultraviolet light, but the desulfurization reaction cannot occur smoothly under the conditions of 380-780 nm visible light or no light. The analysis reason is The Co-Mo/TiO2 catalyst of the present invention is suitable for 200-380 nm ultraviolet light to be excited by electron transition, and 380-780 nm

Visible light cannot stimulate electronic transitions due to insufficient energy level matching. This test shows that the light conditions have a greater influence on the desulfurization effect, and confirms the particularity of the Co-Mo/TiO2 catalyst of the present invention on the light interval. The catalyst of the present invention is a photocatalyst limited to use under the conditions of 200-380 nm ultraviolet light.

[0050] At the same time, the light absorption test of the Co-Mo/TiO2 catalyst and heteropoly acid ((NH4)3Co(0H)6MO6, TiO2, as shown in Figure 7, confirms the light absorption ability of the Co-Mo/TiO2 catalyst of this example, It shows that the ability to absorb light in the spectrum has been significantly improved. Compared with heteropolyacid (NH4)3Co (OH) 6Mo6 and TiO2, its ability to absorb light in the ultraviolet region is significantly enhanced, which confirms that the Co-Mo/TiO2 catalyst of the present invention is resistant to light. Sensitivity of the interval.

Example 2

1) Preparation of [(C18H37)2N (CH3)2] 3Co (OH) 6Mo6O18/TiO2 (ie 2-Co-Mo/TiO2) catalyst: heteropoly acid (C18H37)2N(CH3)2] 3Co (OH) 6M. 6.18: Titanium isopropoxide=3:7 (mass ratio), mix and dissolve in ethanol, adjust pH=6 with ammonia water, stir vigorously for 1 h after the mixture is stable, add hydrofluoric acid (titanium source: hydrofluoric acid) dropwise The molar ratio of acid = 2:1) and continue to stir for 0.5 h before placing it at 200⁰Hydrothermal reaction under c condition for 24 h. After the reaction, it was cooled to room temperature, centrifuged, dried and washed to obtain 2-Co-Mo/TiO2 catalyst. As shown in Figure 8, it is a scanning electron micrograph of the prepared catalyst.

[0052] Desulfurization reaction: Add 20 mL of 400 ppm model oil and 0.1 g of catalyst to the photocatalytic reactor, stir for 0.5h under the conditions of dark, °C, and circulating water temperature control to reach the extraction equilibrium, and then pipette 0.176 Add mL of 30% H2O2 (0/S=5) to the mixed solution, turn on the UV lamp and perform the photocatalytic oxidation reaction experiment (reaction time 3h) under the conditions of 200-380 nm visible light illumination.

[0053] Qualitative and quantitative analysis of the desulfurization reaction: using GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (fid).

[0054] The test results show that: as shown in Figure 10, the 3 h desulfurization rate reached 95%.

[0055] 2) 2-Co-Mo/TiO2 catalyst cycle test: After the reaction, the reaction substrate in the photocatalytic reactor was centrifuged and washed with deionized water and ethanol, and the obtained 2Co-Mo/TiO2 catalyst was collected in an oven It is obtained after drying, and the catalyst can be recycled for desulfurization.

[0056] The same model diesel as in the above-mentioned embodiment was selected, and the separated 2-Co-Mo/TiO2 catalyst was used repeatedly 4 times for deep desulfurization according to the same test parameters and steps.

[0057] After the completion of desulfurization, the qualitative and quantitative analysis of the 4 deep desulfurization tests respectively: as shown in Figure 9, the first 3h desulfurization rate was 95%, the second 3h desulfurization rate was 92%, and the third 3h desulfurization rate was 88 %, the 4th 3h desulfurization rate was 85%, and the 5th desulfurization rate was 83%. It is proved that the heteropolyacid-modified TiO2 photocatalyst of the present invention can be recycled, and the catalytic oxidation effect hardly changes. The difference in the desulfurization effect lies in the inevitable loss of the catalyst during the collection process.

[0058] 3) Heteropoly acid [(C18H37) 2N (CH3) 2] 3Co (oh) 6Mo6O18, TiO2 catalyst comparative test: the same test method steps as the above embodiment, the difference is that the catalyst 2-Co-Mo/ TiO2 was replaced with heteropoly acid [(C18H37)2N(CH3)2] 3Co (OH) 6Mo6O18 catalyst, and the test qualitative and quantitative analysis, as shown in Figure 10, showed that the 3h desulfurization rate was 68%.

[0059] The same test method steps as the above embodiments, the difference is that the catalyst Ni-Mo/TiO2 is replaced with a TiO2 catalyst, and the test qualitative and quantitative analysis, as shown in Figure 10, shows that the 3h desulfurization rate is 49%.

[0060] 4) 380~780 nm visible light comparison test: The same experimental design as the above embodiment, replace the 200~380 nm ultraviolet light illumination condition with 380~780 nm visible light, the test qualitative and quantitative analysis, the test shows that the 3h desulfurization rate is only Is 63%.

[0061] The same experimental design as the above embodiment, replacing the 200-380 nm ultraviolet light illumination condition with no light

Conditions, qualitative and quantitative analysis of the test, the test shows that the 3h desulfurization rate is 42%.

[0062] Example 3 Preparation of [PyPS] 3Co (OH) 6MO6O18/TiO2 (ie 3-Co-Mo/TiO2) catalyst: heteropoly acid (ΝΗ4) 6Μθ7θ24.4H2O: titanium dioxide = 3:7 (mass ratio) mixed, Warm up to 90°C, stir vigorously, then hydrothermally react for 13h. After the reaction, it was cooled to room temperature, centrifuged, dried and washed to obtain a 3-Co-Mo/TiO2 catalyst.

[0063] 1) [PyPS] 3Co (OH) 6Mo6Oi8/TiO2 (ie 3-Co-Mo/TiO2) catalyst: heteropoly acid [PyPS] 3Co (OH) 6Mo6Oi8: titanium isopropoxide 1:7 (mass ratio ) Mix and dissolve in ethanol, adjust pH=5 with ammonia water, stir vigorously for 1 h after the mixture is stable, add hydrofluoric acid (titanium source: hydrofluoric acid molar ratio=3:1) dropwise and continue stirring for 0.5 h Placed at 200 ⁰Hydrothermal reaction under c condition for 24 h. After the reaction, cool to room temperature, centrifuge, dry, wash, and place in a muffle furnace for 1^oThe heating rate of C/min is 450 ⁰c After calcination for 0.5 h, grind to powder to obtain 3-Co-Mo/TiO2 catalyst. Figure 11 shows the XPS valence band spectrum test chart of the prepared catalyst, which proves the synthesis of 3-Co-Mo/TiO2.

[0064] Desulfurization reaction: add 20 mL of 500 ppm model oil and 0.1 g of catalyst to the photocatalytic reactor, stir for 0.5 h under the conditions of dark, °C, and circulating water to reach extraction equilibrium, and then pipette 0.176 mL of 30% H2O2 (O/S=5) was added to the mixed solution, and the photocatalytic oxidation reaction experiment was carried out under the conditions of 200-380 nm ultraviolet light (reaction time 3h).

[0065] Qualitative and quantitative analysis of the desulfurization reaction: using GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

[0066] The test results showed that: as shown in Figure 12, the 3-h desulfurization rate reached 89%.

[0067] 2) 3-Co-Mo/TiO2 catalyst cycle test: After the reaction, the reaction substrate in the photocatalytic reactor was centrifuged and washed with deionized water and ethanol, and the 3Co-Mo/TiO2 catalyst was collected in an oven It is obtained after drying, and the catalyst can be recycled for desulfurization.

[0068] The same model diesel as in the above-mentioned embodiment was selected, and the separated 3-Co-Mo/TiO2 catalyst was used repeatedly 4 times for deep desulfurization according to the same test parameters and steps.

[0069] As shown in Figure 12, after the completion of desulfurization, the qualitative and quantitative analysis of the 4 deep desulfurization tests respectively: the first 3h desulfurization rate was 89%, the second 3h desulfurization rate was 86%, and the third 3h desulfurization rate was 82 %, the fourth 3h desulfurization rate is 80%, which proves that the heteropolyacid-modified TiO2 photocatalyst of the present invention can be recycled, and the catalytic oxidation effect hardly changes. The difference in desulfurization effect is that the catalyst cannot be collected during the collection process. Avoided losses.

[0070] 3) Heteropoly acid [PyPS] 3CO (OH) 6MO6O18, TiO2 catalyst comparative test: the same test method steps as the above embodiment, the difference is that the catalyst 3-Co-Mo/TiO2 is replaced by heteropoly acid [ PyPS] 3CO (OH) 6MO6O18 catalyst, the test qualitative and quantitative analysis showed that the 3h desulfurization rate was 58.8%.

[0071] The same test method steps as the above embodiment, the difference is that the catalyst 3-Co-Mo/TiO2 is replaced with a TiO2 catalyst, and the qualitative and quantitative analysis of the test shows that the 3h desulfurization rate is 47.2%.

[0072] It shows that the 3-Co-Mo/TiO2 of the present invention has a significantly improved catalytic effect. Compared with the use of two catalysts alone, the catalytic efficiency is greatly improved, which proves that the unique structure of the new type of catalyst is more suitable for synthesis. New catalyst for oxidative desulfurization.

[0073] 4) 380 ~ 780 nm visible light comparison test: the same test method steps as the above embodiment, the difference is that the 200 ~ 380 nm ultraviolet light illumination conditions are replaced with 380 ~ 780 nm visible light, the test qualitative and quantitative analysis, the test shows 3h The desulfurization rate is only 57%.

[0074] The same test method steps as the above embodiment, the difference is that the 200~380 nm ultraviolet light illumination conditions are replaced

For the condition without light, the test qualitative and quantitative analysis showed that the desulfurization rate of 3h was 47%.

Example 4

1) Preparation of (NH4) 3Co (OH) 6MO6/TiO2-2 (ie Co-Mo/TiO2-2) catalyst: heteropoly acid (NH4) 3Co (OH) 6MO6: tetrabutyl titanate 1:7 (mass ratio ) Mix and dissolve in ethanol, adjust pH=6 with ammonia water, stir vigorously for 1 h after the mixture is stable, add hydrofluoric acid (titanium source: hydrofluoric acid molar ratio=5:1) dropwise and continue stirring for 0.5 h Placed at 200 ⁰Hydrothermal reaction under c condition for 24 h. After the reaction, cool to room temperature, centrifuge, dry, wash, and place in a muffle furnace for 1^oThe heating rate of C/min is 450 ⁰c After calcination for 0.5 h, the Co-Mo/TiO2-2 catalyst is obtained by grinding to powder. Figure 13 shows the infrared test chart of the prepared catalyst. The peaks of Co, Mo, Ti, and O are accurate, which proves the successful synthesis of Co. -Mo/TiO2-2.

[0076] Desulfurization reaction: Add 20 mL of 450 ppm model oil and 0.1 g of catalyst to the photocatalytic reactor, stir for 0.5h under the conditions of dark, °C, and circulating water, and then reach the extraction equilibrium, and then pipette 0.176 mL of 30% H2O2 (O/S=5) was added to the mixed solution, the UV lamp was turned on, and the photocatalytic oxidation reaction experiment was carried out under the light conditions of 200~380 nm (reaction time 3h).

[0077] Qualitative and quantitative analysis of the desulfurization reaction: using GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

[0078] The test result showed that the desulfurization rate reached 83% in 3 h.

[0079] Experiments show that the effect of using tetrabutyl titanate to prepare heteropolyacid catalyst (83%) is not as good as the effect of titanium isopropoxide (100%). The reason is that the energy level matching degree of the catalyst prepared from titanium isopropoxide and the light system is analyzed. Higher, more conducive to the photocatalytic oxidation reaction.

[0080] 2) Co-Mo/TiO2-2 catalyst cycle test: After the reaction, the reaction substrate in the photocatalytic reactor is washed with deionized water and ethanol by centrifugation, and the collected Co-Mo/TiO2-2 catalyst is It is obtained after drying in the oven, and the catalyst can be recycled for desulfurization.

[0081] The same model diesel as in the above-mentioned embodiment was selected, and the separated Co-Mo/TiO2-2 catalyst was used repeatedly for 3 times for deep desulfurization according to the same test parameters and steps.

[0082] After the completion of desulfurization, the three deep desulfurization tests were qualitatively and quantitatively analyzed: the first 3h desulfurization rate was 83%, the second 3h desulfurization rate was 80%, and the third 3h desulfurization rate was 76%, and the difference in desulfurization effect It lies in the unavoidable loss during the catalyst collection process.

[0083] 3) Light source comparison test: The same test method steps as the above embodiment, the difference is that the ultraviolet light illumination conditions are replaced with 380~780 nm visible light, and the qualitative and quantitative analysis of the test shows that the 3h desulfurization rate is only 59%.

[0084] The same test method steps as the above embodiments, the difference is that the 200-380 nm light conditions are replaced with no light conditions, the test qualitative and quantitative analysis, the test shows that the 3h desulfurization rate is 43%.

[0085] As shown in FIG. 14, the catalytic performance of the catalyst under different illumination conditions. It can be seen from the figure that it has the best desulfurization effect under the ultraviolet illumination conditions of 200 to 380 nm, indicating that this catalyst is more suitable for ultraviolet light conditions.

[0086] Specific examples 1-4 of the present invention show that the deep desulfurization method of diesel fuel and the heteropolyacid-modified TiO2 photocatalyst of the present invention have a strong desulfurization effect under the condition of 200-380 nm ultraviolet light (the best performance 100% complete desulfurization), and the stable and recyclable solid-phase catalyst prepared by the present invention can be recycled, which overcomes the disadvantages that the current catalysts are mostly precious metals and have poor recyclability. It has the advantages of green pollution-free, cheap and easy-to-obtain raw materials, stable and recyclable, etc. advantage.

[0087] The above analysis is due to the organic combination of heteropoly acid and titanium dioxide, and its energy level structure complements each other and forms a stable and recyclable solid phase catalyst. Taking Example 1 as an example, the XPS test shows that the catalyst contains titanium dioxide and heteropoly

The organic combination of acid includes Ti, O, Co, Mo and C elements, and the corresponding binding energy position of each element shows that Co and Mo elements are inserted into the framework of titanium dioxide. The heteropoly acid modified TiO2 photocatalyst of the present invention It has multiple metal active sites, and its catalytic effect can be oxidized with the sulfide (DBT) in the model diesel, and the DBT is oxidized to sulfones and then extracted and separated to achieve deep desulfurization. Also taking Example 1 as an example, as shown in FIG. 7, the catalyst of the present invention has enhanced light absorbing ability in both the 200-780 nm ultraviolet and visible light regions, and in particular, can completely desulfurize under the 200-380 nm ultraviolet light conditions. Further, the calculation of the band gap shows that the catalyst of the present invention is particularly active in electron-hole behavior under the excitation of 200-380 nm ultraviolet light, has a longer electron transport time and a longer electron lifetime, and is effective in catalytic reactions. It can maintain better catalytic activity, which is significantly better than the desulfurization effect under 380~780 nm visible light conditions. As we all know, DBT has stable performance and is not easy to be oxidized. The multi-metal modified catalyst prepared by the present invention and sulfide (DBT) have a strong interaction after being excited by ultraviolet light at 200-380 nm. The molecular energy level of titanium dioxide and heteropoly acid The matching degree is improved, and the utilization rate of the spectrum is greatly improved. Under the condition of hydrogen peroxide catalytic oxidation, DBT is converted into sulfone substances, and a deep desulfurized fuel is obtained through simple separation. The oil overcomes and solves the problem that DBT has stable performance and is not easy to be oxidized.

[0088] In addition, it should be noted that although the desulfurization effect of the heteropolyacid-modified TiO2 photocatalyst within the protection scope of the present invention is slightly different, the best desulfurization effect of Example 1 is compared with Example 4, although The effect of tetrabutyl titanate on the preparation of heteropoly acid catalyst is not as good as the effect of titanium isopropoxide (the reason is that the catalyst prepared by titanium isopropoxide has a higher energy level matching with the light system, which is more conducive to the progress of the catalytic reaction), but it is also far superior Based on the effect of the existing titanium dioxide catalyst photocatalytic diesel desulfurization, the invention solves the problem that the titanium dioxide material used as a diesel photocatalytic oxidative desulfurization catalyst has less energy utilization under ultraviolet light in the sunlight region, and the composite phenomenon of photo-generated electrons and holes seriously leads to low photocatalytic efficiency. The problem.

[0089] The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.