Synthesis Of Hyper Cross-linked Ionic Mesoporous Polymer Monolith And Research Of Deep Oxidative Desulfurization

Solving the serious environmental problems such as acid rain and haze/fog which are caused by sulfur-containing fuels and completing ultra-deep desulfurization have received great attentions worldwide.At present,oxidative desulfurization（ODS）is considered as the most promising route for its low energy consumption,high selectivity and moderate operation conditions.In the meanwhile,porous organic polymer（POPs）materials have tremendously aroused widespread and sustained attention due to their extraordinary inherent structure characteristics such as high specific surface area,tunable pore structure,and versatile organic framework.When applied in catalysis,POPs can provide synergies among dispersion of active sites,simplicity separation and transport properties for the interfacial mass and energy.In this work,the synthesis of the hyper cross-linked ionic mesoporous polymer monolith and its application in deep oxidative desulfurization will be discussed.At first,a facile and scalable one-pot strategy to achieve the hyper cross-linked ionic mesoporous polymer monolith（HCIMPM）is reported.The obtained porous materials were characterized by SEM,TEM、BET,FT-IR,XRD,TG and so on.The effect of the dosage of added P123,the volume of reactive solvent and temperature were discussed respectively.The maximum specific surface area and pore volume are212 m²g^-1 and 1.08 cm³g^-1,respectively.The average pore size is 20.2 nm.Polyoxometalates（POMs）possess tunable acidity,redox properties and high thermal stability.W and Mo-based POMs are the most two commonly used catalytic species.But POMs has low specific surface area and poor catalytic activity.Therefore suitable catalyst carrier is the keynote of ODS.In this work,the organic-inorganic hybrid heterogeneous catalysts,PW/HCIMPM（x）,were prepared by post-modified with 1,4-butanesultone and then loading PW₁₂O₄₀^3-through ion-exchanging.The desulfurization performances of PW/HCIMPM（x）were preliminarily evaluated for the oxidation of DBT in model oil and a～100%of sulfur removal can be acquired after 60 min.The specific reaction conditions were:catalyst（25 mg）,H₂O₂/S=6:1,50°C.Besides the catalytic efficiency and structure of the catalyst showed unapparent changes after six recycles.When applied in real diesel,almost all original sulfur compounds were converted in 120 min which demonstrates the feasibility in practical application.To further study the desulfurization performance of POMs-POPs materials,another function catalyst Mo/HCIMPM was prepared by post-modified with hydrophobic bromooctane and then loaded with Mo₈O₂₆^4-and then used in ODS.A～100%of DBT removal can be acquired after 60 min.The optimized reaction conditions were:catalyst（25 mg）,H₂O₂/S=6:1,50°C.Finally,the catalytic mechanism of Mo₈O₂₆^4-was put forward with the assistant of Raman analysis.