Preparation Method of Boron Nitride-Phosphotungstic Acid High-Efficiency Catalyst

With the increasingly stringent regulations and fuel specifications of the global refining industry, the deep removal of sulfur compounds in fuel oil has attracted more and more attention. In recent years, there have been many different exploration methods, including adsorption desulfurization (ADS). Oxidative desulfurization (ODS) and extractive desulfurization; among them, ODS has attracted great research interest because it can not only react under mild conditions but also exhibit high activity for aromatic sulfur compounds. The key to oxidative desulfurization lies in the synthesis of one. A catalyst having high catalytic activity and easy separation and recovery.

Heteropolyacids (HPAs) with Keggin structure are increasingly used in the catalysis of sulfur compounds; peroxidation of phosphotungstic acid with excess hydrogen peroxide will form peroxygen species W(O2)n, which can catalyze the oxidation of diphenyl And thiophene (DBT), however, because phosphotungstic acid is soluble in the aqueous phase, they are difficult to use in industrial production.

In order to overcome this shortcoming, many researchers have tried to increase the recovery of ODS catalyst by loading phosphotungstic acid onto a solid. Graphene-like boron nitride is a layered material with a high specific surface area. Therefore, loading the phosphotungstic acid onto the graphene-based boron nitride can combine the respective advantages of the two, and can improve the catalytic activity of the catalyst while reducing the amount of the catalyst, and in particular, avoiding potential pollution of the catalyst to the environment. The preparation method of the boron nitride-supported phosphotungstic acid high-efficiency catalyst is as follows:

A graphene-type boron nitride-supported phosphotungstic acid catalyst is synthesized by hydrothermal synthesis, wherein the mass ratio of the graphene-like boron nitride to the phosphotungstic acid is 1:0.1 to 1:0.25, and the specific preparation method comprises the following steps:

(1) According to the mass ratio of 1:0.1~1:0.25, the phosphotungstic acid is added to the absolute ethanol and magnetically stirred at room temperature for 0.5 to 1.5 hours, and then the graphene-based boron nitride is added to continue to disperse and stir 0.5. ~1.5 hours, wherein the mass ratio of the solid reactant to the absolute ethanol is 200 mg: 10 mL.

(2) The mixed liquid is transferred to a high pressure reaction kettle for hydrothermal reaction at 120 to 160 ° C for 4 to 8 hours.

(3) The reaction solution is moved to an oven at 100 to 120 ° C for 10 to 14 hours to obtain the catalyst.

Under the condition of magnetic stirring, a graphene-type boron nitride-supported phosphotungstic acid catalyst and an aqueous solution of H2O2 are added to the fuel for reaction. After the reaction is completed, the upper layer of fuel is poured to separate the catalyst from the fuel; wherein the catalyst is added every 5 ml. The fuel is added 0.02~0.06g, the molar ratio of sulfide to H2O2 in the fuel is 1:2~1:4, the reaction time is 0.5~2 hours, and the reaction temperature is 20~40°C.

The graphene-type boron nitride is used as a carrier to support the high catalytic activity of phosphotungstic acid. The synthesized catalyst is insoluble in oil throughout the reaction process. Therefore, the catalyst has the advantages of high activity of homogeneous catalyst and easy separation of heterogeneous catalyst. The catalyst has high removal efficiency of sulfur, mild catalytic reaction conditions, short reaction time, simple reaction system, convenient catalyst separation and easy recycling.

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