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

Ultraviolet photocatalytic oxidation diesel deep desulfurization method with wavelength of 200~380nm Technical field

The present invention relates to the field of homocatalysis, is a kind of ultraviolet photocatalytic oxidation diesel oil deep desulfurization method of wavelength 200~380nm, relate in particular to a kind of heteropolyacid modified TiO₂A preparation method of a photocatalyst and a diesel desulfurization method under ultraviolet light with a wavelength of 200-380 nm.

Background technique

In recent years, the environmental problems such as the destruction of the atmospheric ozone layer, air pollution, and lack of energy have become increasingly serious, and how to deal with the problem of environmental pollution has become an important subject for scientists to study. With the rapid development of national economic strength, the storage of fossil fuels is depleted day by day, and the continuous exploitation makes its natural storage unsustainable. The post-processing method of directly burning fossil energy is a great challenge to the environment. Sulfur-containing components in automotive diesel will increase SO_xIt will damage the service life of automobile exhaust gas converters and vehicles, and the sulfur content in the exhaust gas is one of the main causes of acid rain, which also causes environmental pollution and damage to human health. However, in today's world's major crude oil energy composition, the vast majority of lower-quality crude oils are high in sulphur. Therefore, exploring the desulfurization process of diesel is one of the important ways to solve the environmental pollution in my country. Controlling the sulfur content in fuel oil and reducing the sulfur content through catalytic conversion is one of the ways to ease environmental pressure and improve energy quality, which meets the requirements of green chemistry.

However, when the diesel-containing sulfur content is lower than 500 ppm, it is difficult to thoroughly remove the sulfur compounds in the diesel oil, and, in the prior art, it is difficult to thoroughly oxidize diesel oil and deeply desulfurize the ultraviolet light related to wavelength 200~380nm. 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 solving the desulfurization method with a sulfur content of fuel oil lower than 500 ppm, and thoroughly removing sulfides.

SUMMARY OF THE INVENTION

Technical problem to be solved by this invention is to provide a kind of deep desulfurization method at wavelength 200~380nm ultraviolet photocatalytic oxidation diesel oil, be further specifically a kind of heteropolyacid modified TiO₂Photocatalyst and preparation method thereof, and method including deep desulfurization of diesel oil.

The present invention solves the above-mentioned technical problem, relates to a kind of deep desulfurization method, and technical scheme is as follows:

Wavelength 200~380nm ultraviolet photocatalytic oxidation diesel deep desulfurization method, step is as follows:

Step 1, titanium source, heteropolyacid are mixed and dissolved in ethanol according to mol ratio 1~5:1, obtain white turbid liquid, adjust pH to 3~6 with alkali, vigorously stir 0.5-2 h to be mixed solution Add hydrofluoric acid dropwise after stabilization, wherein, the molar ratio of hydrofluoric acid and titanium source is 2~5:1, and continue to stir after 0.5-1 h and place 160~200⁰After 20-30 h of hydrothermal reaction under the condition of c, after centrifugation, washing and drying, it was placed in a muffle furnace for 1^oC/min heating rate 350~450⁰c roasting for 0.5~3 h, then take out and grind to powder to obtain heteropolyacid modified TiO₂catalyst of light,

Wherein,

Described titanium source is titanium isopropoxide (Ti[OCH(CH)₃₎₂]₄), tetrabutyl titanate, any one in titanium tetrachloride,

Described heteropolyacid is (NH )₃Co(OH)₆Mo₆, [(C₁₈H₃₇) 2N (CH3) 2]₃co(OH)₆Mo₆O₁₈, [PyPS]₃co(OH)₆Mo₆O₁₈any of the

Described alkali is any one in ammoniacal liquor, sodium hydroxide, sodium bicarbonate;

The TiO modified by the heteropolyacid prepared by step 2, step 1₂The photocatalyst is mixed with DBT in diesel according to the mass ratio of 1~5:1, and then placed in the photocatalytic reactor for 0~60^oC, stirring reaction 0.2~1h reaches extraction equilibrium under the condition of lucifuge and circulating water,

Adding oxygen again comes from the photocatalytic reactor, and in the oxygen source, the elemental element mol ratio of oxygen element and the described diesel oil DBT is 3~5:1, then, at wavelength 200~380 nm ultraviolet light Catalytic oxidative desulfurization reaction completes deep desulfurization in 1~5h under the condition,

Wherein,

The sulfur content of described diesel oil DBT is W500 ppm,

Described oxygen source is H₂O₂, O₂, any one in tert-butyl hydroperoxide;

After step 3, the reaction finishes, stand to layering, and the upper strata diesel oil is poured out by decantation to obtain the diesel oil after the desulfurization.

Preferably it is characterized in that, alkali described in step 1 is ammoniacal liquor.

Preferably it is characterized in that, titanium source described in step 1 is titanium isopropoxide (Ti[OCH(CH)₃₎₂]₄)。

Preferably characterized in that, in step 1, regulate pH to 5~6.

Preferably, it is characterized in that, in step 1, hydrothermal reaction temperature is 200 °C.

Preferably it is characterized in that, oxygen source described in step 2 is H₂O₂。

The present invention solves another technical problem, relates to a kind of photocatalyst of deep desulfurization, and technical scheme is as follows:

The described heteropolyacid-modified TiO prepared by step 1 in above-mentioned diesel oil deep desulfurization method₂Photocatalyst, suitable for catalytic oxidation deep desulfurization under the condition of ultraviolet light with wavelength of 200~380 nm.

[0025] It is well known that DBT has stable properties and is not easily oxidized. The innovative feature of the present invention lies in the heteropolyacid modified TiO₂The photocatalyst improves the energy level matching degree in the photocatalytic system, so that the sulfide (DBT) in the model diesel is catalyzed and oxidized to sulfones and then extracted and separated to achieve deep desulfurization; further analysis, the catalyst prepared by the present invention utilizes the heteropolyacid. Titanium dioxide is modified with energy level tunable properties, and the catalyst energy level combined with titanium dioxide is adjusted by changing the types and amounts of different heteropolyacids to form a stable and recyclable solid-phase catalyst; further, as shown in Figure 1, at the wavelength of Under the condition of 200~380nm ultraviolet light, the energy level of the catalyst modified by the heteropolyacid prepared by the present invention changes, and according to the type of the heteropolyacid and the central atom, the conduction band of the main catalyst titanium dioxide will move down, and the forbidden band width will decrease, The utilization rate of the catalyst to sunlight is improved, the catalyst is more sensitive to sulfur-containing compounds (DBT) in diesel, the performance of photogenerated electrons and holes is improved, and it has a faster electron transport rate and a longer electron transport distance. , under the activation of oxidant, DBT can be oxidized more efficiently to generate sulfones, and sulfones can be separated to obtain fuel with extremely low sulfur content by a simple separation method, thus solving the problem of insufficient energy level matching of diesel photocatalytic oxidative desulfurization catalysts High, photogenerated electron and hole transport rates and transport distances are not ideal, resulting in low photocatalytic efficiency.

Beneficial effect of the present invention is:

1) technological process of the present invention is simple to operate, and reaction conditions are gentle, and, the TiO modified by heteropolyacid of the present invention₂Photocatalysts can be recycled.

2) deep desulfurization of diesel oil of the present invention is effective to ultraviolet light at wavelength 200~380nm.

3) the inventive method can reach 90%~100% only at wavelength 200~380nm ultraviolet light desulfurization effect, has the photoselectivity of deep desulfurization, and is far higher than prior art titanium dioxide photocatalytic desulfurization effect (W50%) , where the optimal (NH₄) ₃Co(OH)₆Mo₆/TiO₂ (i.e. Co-Mo/TiO₂) The catalyst desulfurization rate can reach 100% to completely remove sulfur.

4) the deep desulfurization reaction time of diesel oil of the present invention is short, and the reaction can be completed in 1~5 h.

5) the present invention can not only selectively remove sulfur in diesel oil at the depth of wavelength 200-380nm ultraviolet light process

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

Description of drawings

[0032] The accompanying drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part, together with the specific embodiments of the application, to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

Fig. 1 is the catalytic performance mechanism of desulfurization process of the present invention.

Fig. 2 is the catalyst SEM test chart prepared by the embodiment of the present invention 1.

Fig. 3 is the catalysis and UXRD test chart prepared by the embodiment of the present invention 1.

Fig. 4 is the catalytic performance test figure (cycle 5 times) of the catalyst recycling of the embodiment of the present invention 1.

Fig. 5 is (Co-Mo/TiO) of the embodiment of the present invention 1₂, (NH₄) ₃co(OH)₆Mo₆, TiO₂) Comparison of catalytic effects.

Fig. 6 is (380~780 nm, 200~380 nm, lucifuge) catalyst catalytic performance test figure under the different illumination conditions of the embodiment of the present invention 1.

Fig. 7 is the embodiment of the present invention 1 different catalysts (Co-Mo/TiO₂, (NH₄) ₃co(OH)₆Mo₆, TiO₂) light absorption ability test chart.

Fig. 8 is the embodiment of the present invention 2 catalyst Ni-Mo/TiO₂SEM image.

Fig. 9 is the catalytic performance test figure (cycle 5 times) of the catalyst recycling of the embodiment of the present invention 2.

Fig. 10 is the embodiment of the present invention 2 catalyst 2-Co-Mo/TiO₂, [(C₁₈H₃₇)₂N(CH₃)₂]₃co(OH)₆Mo₆O₁₈and TiO₂Catalytic performance test chart.

Fig. 11 is the embodiment of the present invention 3 catalyst 3-Co-Mo/TiO₂The XPS mid-valence band spectrum test chart.

Fig. 12 is the catalytic performance test figure (cycle 4 times) of the embodiment of the present invention 3 catalyst recycling.

Fig. 13 is the catalyst infrared test chart prepared by the embodiment of the present invention 4.

Fig. 14 is (380~780 nm, 200~380 nm, lucifuge) catalyst catalytic performance test figure under the different illumination conditions of the catalyst prepared by the embodiment of the present invention 4.

detailed description

[0047] The present invention will be described in more detail below with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown, and 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 construed as widely known to those skilled in the art and not as a limitation of the present invention.

[0048] In the interest of clarity, not all features of an actual embodiment are described. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention with unnecessary detail. It should be recognized that in the development of any actual embodiment, a number of implementation details must be made to achieve the developer's specific goals.

Principle of the present invention and feature are described below, given examples are only used to explain the present invention, not to limit the scope of the present invention, and it should be noted that it is the model diesel DBT content W500 ppm tested in the following examples .

Embodiment 1

1) preparation (NH )₃Co(OH)₆Mo₆/TiO₂ (i.e. Co-Mo/TiO₂) Catalyst: Heteropolyacid (NH4)₃co(OH)6Mo6:

Titanium isopropoxide=1:7 (mass ratio), mixed and dissolved in ethanol, adjusted pH=5 with ammonia water, vigorously stirred for 1 h and after the mixture was stabilized, added hydrofluoric acid (titanium source: molar ratio of hydrofluoric acid) dropwise =5:1) and continue stirring for 0.5 h and then placed at 200⁰Hydrothermal reaction under the condition c

should be 24 hours. After the reaction was completed, it was cooled to room temperature, centrifuged, dried, washed, and placed in a muffle furnace for 1^oC/min heating rate at 450⁰c After calcination for 0.5 h, grind to powder to obtain Co-Mo/TiO₂The catalyst, as shown in the electron microscope test in Fig. 2, is in the form of round nanoparticles.

The catalyst XRD test of Fig. 3 shows the organic combination of titanium dioxide and heteropolyacid in the catalyst, mainly showing TiO₂The characteristic peaks of , and the XPS test shows that it contains Ti, O, Co, Mo and C elements, which proves that Co-Mo/TiO₂Successful synthesis of catalysts.

Desulfurization reaction: add the model oil of 20 mL 500 ppm, catalyzer 0.1 g in photocatalytic reactor, reach extraction equilibrium after stirring 0.5h under lucifuge, °C, circulating water condition,

Then, pipette 0.176 mL of 30% H O (O/S=5) and add in the mixed solution, open the xenon lamp and carry out the photocatalytic oxidation reaction experiment (reaction time 3h) under 200~380 nm ultraviolet light illumination conditions.

Desulfurization reaction qualitative and quantitative analysis: adopt GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

Test result shows: the catalyst desulfurization rate of 30% content after 3 h can all reach 100%.

2) Co-Mo/TiO₂Catalyst cycle test:

After the reaction finishes, the reaction substrate in the photocatalytic reactor is centrifugally washed with deionized water and ethanol, and the Co-Mo/TiO that obtains is collected₂The catalyst is obtained after drying in an oven, and then the catalyst is recycled for desulfurization.

Choose the model diesel oil identical with above-mentioned embodiment, according to identical test parameter and step method, will separate Co-Mo/TiO₂The catalyst was repeatedly used for 5 times for deep desulfurization.

After the desulfurization is completed, the qualitative and quantitative analysis of 5 deep desulfurization tests are respectively: as shown in Figure 4, the 1st 3h desulfurization rate is 100%, the 2nd 3h desulfurization rate is 100%, and the 3rd 3h desulfurization rate is 98.2 %, the 4th 3h desulfurization rate is 97.5%, and the 5th 3h desulfurization rate is 95.3%, which proves that the TiO modified by the heteropolyacid of the present invention₂The photocatalyst can be recycled, and the catalytic oxidation effect hardly changes, wherein the difference in the desulfurization effect lies in the unavoidable mass loss in the catalyst recovery process.

3) heteropolyacid (NH )₃Co(OH)₆Mo₆, TiO₂Comparative test of catalyst:

The same test method steps as above-mentioned embodiment, difference is that described catalyst Co-Mo/TiO₂Replaced with heteropolyacid (NH4)₃Co(OH)₆Mo₆Catalyst, the qualitative and quantitative analysis of the test showed that the desulfurization rate in 3h was 85.2%.

The same test method steps as above-mentioned embodiment, difference is that described catalyst Co-Mo/TiO₂Replaced with TiO₂Catalyst, the qualitative and quantitative analysis of the test showed that the desulfurization rate of 3h was 63.6%.

As shown in Figure 5, the Co-Mo/TiO₂Catalyst and Heteropolyacid (NH₄) ₃co(OH)₆Mo₆, TiO₂Compared with the catalyst, Co-Mo/TiO₂The catalyst can be completely desulfurized under the condition of 200-380 nm UV light. It shows that the catalyst of the present invention has significantly improved catalytic effect. Compared with using the two catalysts alone, the catalytic efficiency is greatly improved, which proves the unique structure of the synthesized new catalyst, which is a new type of catalyst more suitable for oxidative desulfurization.

4) 380~780 nm visible light contrast test:

The same test method step as above-described embodiment, difference is that 200-380 nm ultraviolet light illumination condition is replaced with 380~780 nm visible light, test qualitative and quantitative analysis, test shows that 3h desulfurization rate is only 78%.

The same test method steps as above-described embodiment, difference is that 200-380 nm ultraviolet light illumination condition is replaced with the condition that does not have illumination, test qualitative and quantitative analysis, test shows 3h desulfurization rate is 58%.

As shown in Figure 6, under the condition of 200-380 nm ultraviolet light, the catalyst of the present invention can only be 100% desulfurized, but desulfurization reaction cannot smoothly occur under the condition of 380-780 nm visible light or without illumination, and the analysis reason is that Co-Mo/TiO of the present invention₂The catalyst is suitable for 200~380 nm ultraviolet light excitation, and electron transitions are more likely to occur, while 380~780 nm

Visible light cannot excite electron transitions due to insufficient energy level matching. This test shows that the light condition has a great influence on the desulfurization effect, which confirms the Co-Mo/TiO of the present invention.₂The particularity of the catalyst to the illumination interval, the catalyst of the present invention is a photocatalyst limited to use under the condition of 200-380 nm ultraviolet light.

At the same time, for Co-Mo/TiO₂Catalyst and heteropolyacid ((NH₄)₃co(OH)₆Mo₆, TiO₂The light absorption test, shown in Figure 7, confirms the Co-Mo/TiO of this example₂The light-absorbing ability of the catalyst, which shows a significant increase in the ability to absorb light in the spectrum, is comparable to that of heteropolyacids (NH₄)₃co(OH)₆Mo₆, TiO₂Compared with the above, its light absorption ability in the ultraviolet region is significantly enhanced, confirming that the Co-Mo/TiO of the present invention₂Sensitivity of the catalyst to the illumination interval.

Embodiment 2

1) preparation [(C₁₈H₃₇) ₂N (CH3)₂] ₃Co(OH)₆Mo₆O₁₈/TiO₂ (i.e. 2-Co-Mo/TiO₂)catalyst:

Heteropolyacid (C₁₈H₃₇) ₂N (CH3)₂] ₃Co(OH)₆Mo₆O₁₈: 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: moles of hydrofluoric acid) dropwise ratio = 2: 1) and continue stirring for 0.5 h and then placed at 200⁰The hydrothermal reaction was carried out under the condition of c for 24 h. After the reaction was completed, it was cooled to room temperature, centrifuged, dried and washed to obtain 2-Co-Mo/TiO₂catalyst. As shown in Figure 8, it is a scanning electron microscope image of the prepared catalyst.

Desulfurization reaction: add the model oil of 20 mL 400 ppm, catalyzer 0.1 g in photocatalytic reactor, reach extraction equilibrium after stirring 0.5h under lucifuge, °C, circulating water temperature control condition,

Then, pipette 0.176 mL of 30% H O (O/S=5) and add in mixed solution, turn on ultraviolet lamp and carry out photocatalytic oxidation reaction experiment (reaction time 3h) under 200~380 nm visible light illumination conditions.

Desulfurization reaction qualitative and quantitative analysis: adopt GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

Test result shows: as shown in Figure 10, 3 h desulfurization rate reaches 95%.

2) 2-Co-Mo/TiO₂Catalyst cycle test:

After the reaction finishes, the reaction substrate in the photocatalytic reactor is centrifugally washed with deionized water and ethanol, and the 2-Co-Mo/TiO that obtains is collected₂The catalyst is obtained after drying in an oven, and the catalyst can be recycled for desulfurization.

Choose the model diesel oil identical with above-mentioned embodiment, according to identical test parameter and step method, separate 2-Co-Mo/TiO₂The catalyst was reused 4 times for deep desulfurization.

After the desulfurization is completed, the qualitative and quantitative analysis of 4 deep desulfurization tests are respectively: as shown in Figure 9, the 1st 3h desulfurization rate is 95%, the 2nd 3h desulfurization rate is 92%, and the 3rd 3h desulfurization rate is 88%. %, the 4th 3h desulfurization rate was 85%, and the 5th desulfurization rate was 83%. Demonstration of the heteropolyacid modified TiO of the present invention₂The photocatalyst can be recycled, and the catalytic oxidation effect hardly changes, and the difference in the desulfurization effect lies in the inevitable loss during the collection process of the catalyst.

3) heteropolyacid [(C₁₈H₃₇) ₂N(CH₃) ₂] ₃co(OH)₆Mo₆O₁₈, TiO₂Comparative test of catalyst:

The same test method steps as above-mentioned embodiment, difference is that will catalyze 2-Co-Mo/TiO₂replaced by heteropolyacid [(C₁₈H₃₇) ₂N (CH3)₂1₃co(OH)₆Mo₆O₁₈Catalyst, qualitative and quantitative analysis of the test, as shown in Figure 10, the test shows that the desulfurization rate of 3h is 68%.

The same test method steps as above-mentioned embodiment, difference is that catalyst Ni-Mo/TiO₂Replaced with TiO₂Catalyst, qualitative and quantitative analysis of the test, as shown in Figure 10, the test shows that the desulfurization rate of 3h is 49%.

4) 380~780 nm visible light contrast test:

[0085] The same experimental design as the above-described embodiment, the 200-380 nm ultraviolet light illumination condition is replaced by 380-780 nm visible light, and the qualitative and quantitative analysis of the test shows that the test shows that the 3h desulfurization rate is only 63%.

The experimental design identical with the above-described embodiment, the 200-380 nm ultraviolet light illumination condition is replaced with no illumination

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

Embodiment 3

Preparation [PyPS]₃co(OH)₆Mo₆O₁₈/TiO₂ (ie 3-Co "Mo/TiO₂)catalyst:

Heteropolyacid (NH₄)₆Mo₇O₂₄·4H₂O: Titanium dioxide=3:7 (mass ratio) mixed, heated to 90°C, vigorously stirred, and then hydrothermally reacted for 13h. After the reaction was completed, it was cooled to room temperature, centrifuged, dried and washed to obtain 3-Co-Mo/TiO₂catalyst.

1) system [PyPS]₃Co(OH)₆Mo₆O₁₈/TiO₂ (ie 3-Co "Mo/TiO₂) Catalyst: Heteropolyacid [PyPS]₃co(OH)₆Mo₆O₁₈: Titanium isopropoxide 1:7 (mass ratio) was mixed and dissolved in ethanol, adjusted pH=5 with ammonia water, vigorously stirred for 1 h and after the mixture was stable, hydrofluoric acid (titanium source: molar ratio of hydrofluoric acid) was added dropwise =3:1) and continue stirring for 0.5 h and then placed at 200⁰The hydrothermal reaction was carried out under the condition of c for 24 h. After the reaction was completed, it was cooled to room temperature, centrifuged, dried, washed, and placed in a muffle furnace for 1^oC/min heating rate at 450⁰c After calcination for 0.5 h, grind to powder to obtain 3-Co-Mo/TiO₂catalyst. Figure 11 shows the XPS valence band spectrum test chart of the prepared catalyst, which proves that 3-Co-Mo/TiO was synthesized.₂。

Desulfurization reaction: add the model oil of 20 mL 500 ppm, catalyzer 0.1 g in photocatalytic reactor, reach extraction equilibrium after stirring 0.5h under lucifuge, °C, circulating water condition,

Then, pipette 0.176 mL of 30% H O (O/S=5) and add in the mixed solution, carry out photocatalytic oxidation reaction experiment (reaction time 3h) under 200~380 nm ultraviolet light illumination conditions.

Desulfurization reaction qualitative and quantitative analysis: adopt GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

Test result shows: as shown in Figure 12, 3 h desulfurization rate reaches 89%.

2) 3-Co-Mo/TiO₂Catalyst cycle test:

After the reaction finishes, the reaction substrate in the photocatalytic reactor is centrifugally washed with deionized water and ethanol, and the 3-Co-Mo/TiO that obtains is collected₂The catalyst is obtained after drying in an oven, and the catalyst can be recycled for desulfurization.

Choose the model diesel oil identical with above-mentioned embodiment, according to identical test parameter and step method, will separate 3-Co-Mo/TiO₂The catalyst was reused 4 times for deep desulfurization.

As shown in Figure 12, after the desulfurization is completed, the qualitative and quantitative analysis of 4 deep desulfurization tests are respectively: the 1st 3h desulfurization rate is 89%, the 2nd 3h desulfurization rate is 86%, and the 3rd 3h desulfurization rate is 82%. %, the desulfurization rate of the fourth 3h is 80%, which proves that the TiO modified by the heteropolyacid of the present invention₂The photocatalyst can be recycled, and the catalytic oxidation effect hardly changes, and the difference in the desulfurization effect lies in the inevitable loss during the collection process of the catalyst.

3) Heteropolyacid [PyPS]₃co(OH)₆Mo₆O₁₈, TiO₂Comparative test of catalyst:

[0100] The same test method steps as the above-mentioned embodiment, the difference is that the catalyst 3-Co-Mo/TiO₂Replaced with Heteropolyacid [PyPS]₃Co(OH)₆Mo₆O₁₈Catalyst, the qualitative and quantitative analysis of the test showed that the desulfurization rate in 3h was 58.8%.

[0101] The same test method steps as the above-mentioned embodiment, the difference is that the catalyst 3-Co-Mo/TiO₂Replaced with TiO₂Catalyst, the qualitative and quantitative analysis of the test showed that the desulfurization rate in 3h was 47.2%.

Illustrating the 3-Co-Mo/TiO of the present invention₂Compared with using the two catalysts alone, the catalytic efficiency is greatly improved, which proves that the unique structure of the synthesized new catalyst is a new type of catalyst more suitable for oxidative desulfurization.

4) 380~780 nm visible light contrast test:

The same test method steps as above-described embodiment, difference is that 200-380 nm ultraviolet light illumination condition is replaced with 380~780 nm visible light, test qualitative and quantitative analysis, test shows 3h desulfurization rate is only 57%.

The same test method step with above-described embodiment, difference is to replace 200-380 nm ultraviolet light illumination condition

For the condition of no light, the qualitative and quantitative analysis of the test shows that the desulfurization rate of 3h is 47%.

Embodiment 4

1) Preparation (NH₄) ₃Co(OH)₆Mo₆/TiO₂-2 (i.e. Co-Mo/TiO₂"2) Catalyst: Heteropolyacid (NH₄) ₃co(OH)₆Mo₆: Mix tetrabutyl titanate 1:7 (mass ratio) 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: mole of hydrofluoric acid) dropwise ratio = 5:1) and continue stirring for 0.5 h and then placed at 200⁰The hydrothermal reaction was carried out under the condition of c for 24 h. After the reaction was completed, it was cooled to room temperature, centrifuged, dried, washed, and placed in a muffle furnace for 1^oC/min heating rate at 450⁰c After calcination for 0.5 h, grind to powder to obtain Co-Mo/TiO₂-2 catalyst, as shown in Figure 13 is the infrared test chart of the prepared catalyst. The peaks of Co, Mo, Ti, and O elements are accurate, which proves that Co-Mo/TiO was successfully synthesized.₂-2。

Desulfurization reaction: in photocatalytic reactor, add the model oil of 20 mL 450 ppm, catalyzer 0.1 g, reach extraction equilibrium after stirring 0.5h under lucifuge, °C, circulating water condition,

Then, pipette 0.176 mL of 30% H O (O/S=5) and add in the mixed solution, turn on the ultraviolet lamp and carry out the photocatalytic oxidation reaction experiment (reaction time 3h) under 200~380 nm illumination conditions.

Desulfurization reaction qualitative and quantitative analysis: adopt GC (FuLi 9750, HP-5 column), chromatographic column: DB-1 capillary chromatographic column, detector: hydrogen flame ionization detector (FID).

Test result shows: 3 h desulfurization rate reaches 83%.

Test shows that using tetrabutyl titanate to prepare heteropolyacid catalyst effect (83%) is not as good as titanium isopropoxide effect (100%), the analysis reason is that the catalyst prepared by titanium isopropoxide and the energy level matching degree of illumination system higher, which is more conducive to the photocatalytic oxidation reaction.

2) Co-Mo/TiO₂-2 Catalyst cycle test:

After the reaction finishes, the reaction substrate in the photocatalytic reactor is centrifugally washed with deionized water and ethanol, and the Co-Mo/TiO that obtains is collected₂-2 The catalyst is obtained after drying in an oven, and the catalyst can be recycled for desulfurization.

Choose the model diesel oil identical with above-mentioned embodiment, according to identical test parameter and step method, separate Co-Mo/TiO₂-2 The catalyst is repeated 3 times for deep desulfurization.

After the desulfurization is completed, the qualitative and quantitative analysis of 3 deep desulfurization tests are respectively: the 1st 3h desulfurization rate is 83%, the 2nd 3h desulfurization rate is 80%, the 3rd 3h desulfurization rate is 76%, the difference of the desulfurization effect lies in the unavoidable losses during the catalyst collection process.

3) light source contrast test:

[0118] The same test method step as the above-described embodiment, the difference is that the ultraviolet light illumination condition is 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%.

The same test method steps as above-mentioned embodiment, difference is that 200~380 nm light conditions are replaced with the condition that does not have light, test qualitative and quantitative analysis, test shows 3h desulfurization rate is 43%.

As shown in Figure 14, it is the catalyst catalytic performance under different illumination conditions, as can be seen from the figure, under 200~380 nm ultraviolet illumination conditions, have the best desulfurization effect, illustrate that this catalyst is more suitable for ultraviolet illumination conditions.

Specific embodiments 1-4 of the present invention show that the deep desulfurization method of diesel oil of the present invention and the TiO modified by heteropolyacid₂The photocatalyst has a strong desulfurization effect under the condition of 200-380 nm ultraviolet light (the best can be 100% complete desulfurization), and the stable and recyclable solid-phase catalyst prepared by the present invention can be recycled, which overcomes the fact that most catalysts are precious metals at present. In addition, it has the disadvantage of poor recyclability, and has the advantages of green and pollution-free, cheap and easy-to-obtain raw materials, and stable and recyclable.

Above, analysis reason is that heteropolyacid is organically combined with titanium dioxide, and its energy level structure complements and matches each other and forms a stable and recyclable solid-phase catalyst. Taking Example 1 as an example, XPS test shows that titanium dioxide and heteropoly are in the catalyst.

The organic combination of acid includes Ti, O, Co, Mo and C elements, and the binding energy position corresponding to each element shows that Co, Mo elements are inserted into the framework of titanium dioxide, the TiO modified by the heteropolyacid of the present invention₂The photocatalyst has multiple metal active sites, and its catalytic effect can be oxidized with sulfide (DBT) in model diesel, and DBT can be oxidized to sulfones and then extracted and separated to achieve deep desulfurization. Also take Example 1 as an example to illustrate, as shown in Figure 7, the catalyzer of the present invention is all enhanced in 200~780 nm ultraviolet and visible light region light absorption ability, especially can be completely and thoroughly desulfurized under 200~380 nm ultraviolet light condition. Further, it can be seen from the calculation of the forbidden band width that the catalyst of the present invention has more active electron-hole behavior, especially under the excitation of 200-380 nm ultraviolet light, has a longer electron transport time and a longer electron lifetime, and is in the catalytic reaction. It can maintain better catalytic activity, which is obviously better than the desulfurization effect under the condition of 380~780 nm visible light. It is well known that 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 excitation by ultraviolet light at 200-380 nm, and the molecular energy level of titanium dioxide and heteropolyacid The matching degree is improved, and the utilization rate of the spectrum is greatly improved. DBT is converted into sulfones under the condition of hydrogen peroxide catalytic oxidation, and deeply desulfurized fuel oil is obtained through simple separation, which overcomes and solves the problem that DBT has stable performance and is not easily oxidized.

In addition, it should be noted that the heteropolyacid-modified TiO within the protection scope of the present invention₂Although the desulfurization effect of the photocatalyst is slightly different, comparing Example 1 with the best desulfurization effect with Example 4, although the effect of preparing the heteropolyacid catalyst from tetrabutyl titanate is not as good as the effect of titanium isopropoxide (the reason is that the isopropanol The catalyst prepared from titanium has a higher energy level matching degree with the illumination system, which is more conducive to the catalytic reaction), but it is also far superior to the effect of the existing titanium dioxide catalyst for photocatalytic diesel desulfurization. Oxidative desulfurization catalysts have less energy utilization under ultraviolet light in the solar region, and the recombination of photogenerated electrons and holes seriously leads to the problem of low photocatalytic efficiency.

[0124] The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.