Study On Photocatalytic Oxidation Desulfurization Performance Of SBA-15 Modified By BiVO₄

With the continuous development of the times,motor vehicles have become an indispensable means of transportation for people to travel,which has greatly improved people’s quality of life.At the same time,the large amount of sulfur emissions caused by the burning of motor fuel oil not only poses a great threat to human health,but also brings serious environmental pollution,which runs counter to the sustainable development strategy.In order to alleviate environmental pressure and ensure the stability and healthy development of the ecosystem,it is necessary to further standardize the fuel oil quality indicators.Therefore,it is worthwhile to study the reduction of sulfur compounds in fuel oil and the production of high-quality low-sulfur diesel.In addition,the traditional benzaldehyde preparation method is complicated in operation and seriously pollutes the environment.Considering the increasing demand of benzaldehyde,the preparation process of simple and mild conditions of benzaldehyde is of great significance.Among many catalytic processes,photocatalytic oxidative desulfurization technology has attracted much attention due to its wide application range,mild and simple operating conditions,low operating and operating costs,energy saving and environmental protection,and high catalytic efficiency.It can be used to assist hydrodesulfurization to achieve ultra-deep desulfurization of diesel,which has broad development prospects.In this paper,BiVO₄/SBA-15 high-efficiency photocatalyst was successfully prepared by SBA-15 molecular sieve as carrier and hydrothermal synthesis.The BiVO₄/SBA-15 photocatalyst was characterized by X-ray diffraction（XRD）,N₂ adsorption-desorption（BET）,scanning electron microscopy-X-ray spectroscopy（SEM-EDS）,transmission electron microscopy（TEM）,fourier infrared analysis（FT-IR）,UV-visible the physicochemical properties of the catalyst were analyzed by means of spectroscopy（UV-Vis）and thermogravimetry-differential thermal analysis（TG-DTA）.The results showed that the prepared BiVO₄/SBA-15photocatalyst has a regular mesoporous structure,and the active component BiVO₄ is highly uniformly dispersed on the surface of the SBA-15molecular sieve.In this paper,in the self-made photocatalytic reactor,BiVO₄/SBA-15high-efficiency photocatalyst was used to prepare the benzaldehyde reaction as a probe reaction.The effects of BiVO₄/SBA-15 hydrothermal time,BiVO₄ loading,BiVO₄/SBA-15 calcination time and calcination temperature on the desulfurization performance of the catalyst were investigated.The results show that the BiVO₄/SBA-15 catalyst has the best catalytic effect when the hydrothermal time of BiVO₄/SBA-15 is 18h,the loading of BiVO₄ is 15%,the calcination temperature is 530℃,and the calcination time is 3h.The BiVO₄/SBA-15 photocatalyst with the best catalytic effect was applied to the experiment of styrene oxidation to benzaldehyde.The best experimental conditions were determined as follows:BiVO₄/SBA-15:styrene（mass ratio）=10%,reaction temperature of 70℃,reaction time of 2.5 hours,styrene:acetone:H₂O₂（molar ratio）=1:2:3.5.Then the BiVO₄/SBA-15 photocatalyst with the best catalytic effect was applied to the desulfurization experiment of static photocatalytic oxidation simulated diesel.The best experimental conditions were determined as follows:the amount of BiVO₄/SBA-15 was 15g/L,n（O）/n（S）=2.0,the reaction temperature was 60℃,the reaction time was 3hours,and the ratio of agent to oil was 1:1.Under the experimental conditions,the simulated diesel desulfurization rate of BiVO₄/SBA-15reached 95.58%.