Synthesis Of New Metal-Organic Frameworks And Their Applications In Adsorptive Desulfurization

Gasoline contains many sulfur compounds,these compounds will release a lot of toxic substances through the combustion,Endangering the atmosphere.Therefore,to find an effective way to reduce the sulfur content of gasoline becomes a major problem that people need to solve.And due to its relatively mild operating conditions that do not need H2 and catalyst,etc.,adsorption desulfurization becomes one of the potential methods that can remove them.One of the keys is that the choice of efficient adsorbent,and the current commonly used adsorbents,including activated carbon,zeolite,etc.,but the adsorption capacity has not yet meet the actual needs.In recent years,metal-organic frameworks(MOFs)have gradually become one of the hotspots in the field of materials?chemistry and chemical industry.They have the advantages of high porosity?specific surface area and high pore size,that are widely concerned.And it is applied to gasoline desulfurization,and achieved certain results,but for the removal of thiophene compounds,there is still a relatively low adsorption capacity,the adsorption effect is not good enough.In this work,the desulfurization effect of metal-organic framework materials on gasoline was systematically studied.We select benzothiophene(BT),dibenzothiophene(DBT)and 4,6-DMDBT as the adsorbate,PCN-10?Zn@PCN-10 and PTA@PCN-10 were used as adsorbents to study the effect on the adsorption of three sulfides,The main specific research contents are as follows1.The synthesis of MOFs.PCN-10?Zn@PCN-10 and PTA@PCN-10 were prepared by using the existing equipment and conditions in the laboratory.According to the theory of soft and hard acid and alkali,it can improve the soft acidity by modifying Zn2+ with PCN-10,while BT and DBT show soft and alkaline,and the MOFs interacts with the adsorbate,thereby increasing their adsorption capacity.According to the interaction between acid and alkali,PCN-10 was modified with phosphotungstic acid(PTA),which could improve the acidity of PCN-10,and improve the adsorption of 4,6-DMDBT.The BET,powder X-ray diffraction,infrared spectroscopy,thermogravimetric analysis were used to characterize the synthesized materials..2.The adsorption effect of PCN-10 on BT and 4,6-DMDBT were studied.The results showed that the adsorption capacity of PCN-10 to BT and 4,6-DMDBT is 61.64 mgS·g-1MOF and 34.81 mg·Sg-1MOF,respectively,and the effect is higher than that of many MOF materials and molecular sieves such as MIL-53(Al).3.The effects of different Zn doping amounts of Zn@PCN-10,Zn/PCN-10 and PTA@PCN-10 on the removal of three sulfides were studied.The results showed that the adsorption effect of Zn@PCN-10 on DBT and BT was good,the adsorption capacities were 84.65 mgS g 'MOF and 68.44 mgS·g-1MOF,respectively,which were 11%and 10%higher than that before modification.PTA@PCN-10 had better effect on 4,6-DMDBT,and the adsorption capacity was 38.79 mgS·g-1MOF,which was about 11.5%higher than that before modification.The above results indicate that the central metal,acid and so on of the MOFs skeleton have an important effect on the removal of thiophenes.These laws have a certain guiding effect on the subsequent adsorption desulfurization work.